Chemical Testing of Commercial Vessel Personnel

An Analysis of Archived Test Results

by

Walter J. Brudzinski, JD, Ph.D.

Chief Administrative Law Judge

U.S. Coast Guard

© by Walter J. Brudzinski 2013

All Rights Reserved
i

ABSTRACT

The United States Coast Guard implemented chemical testing to discourage drug 

and alcohol use by commercial vessel personnel, reduce the potential for marine 

casualties related to drug and alcohol use, and enhance the safety of the maritime 

transportation industry. This study shows the extent chemical testing might achieve these 

U.S. Coast Guard goals through a secondary data analysis of samples from two archived 

databases from 2003-2011. The first database is the Management Information System 

containing drug testing results marine employers submit to the Coast Guard each year. 

The second consists of Serious Marine Incident reports containing Post-Accident drug 

and alcohol test results from two vessel categories – those with no crewmember chemical 

testing requirements except for Post-Accident drugs and alcohol and the other with 

comprehensive crewmember chemical testing requirements. Chemical testing includes 

Pre-Employment, Periodic, Random, Reasonable Cause, and Post-Accident. Alcohol 

testing is conducted Post-Accident only. This study compared the following: 1) PostAccident drug and alcohol positivity rates between the two vessel categories; 2) Yearly 

ratios of Post-Accident drug and alcohol positive tests to serious marine incidents of each 

vessel category; and, 3) Random to Post-Accident drug test positivity rates from all 

commercial vessel personnel subject to chemical testing. Using percentages, tables, 

graphs, the correlation coefficient, linear regression, and the two proportion z-test, this 

study found that chemical testing appears to have discouraged drug and alcohol use by 

commercial vessel personnel, reduced the potential for marine casualties related to drug 

and alcohol use, and enhanced the safety of the maritime transportation industry. 
ii

TABLE OF CONTENTS

 

Acknowledgement i

Abstract ii

Table of Contents iii

Chapter I. Introduction 1

Chapter II. Literature Review 15

Chapter III. Methodology 36

Chapter IV. Analysis 47

Chapter V. Hypothesis 1A 51

Chapter VI. Hypothesis 1B 56

Chapter VII. Hypothesis 1C 61

Chapter VIII. Hypothesis 2A 66

Chapter IX. Hypothesis 2B 71

Chapter X. Hypothesis 3 76

 

Chapter XI. Discussion 84

Bibliography 94
iii

LIST OF TABLES

Table 1 Quest Drug Testing Index: Combined U.S. workforce 2003-2011 33

Table 2 Quest Drug Testing Index: Federally-mandated safety-sensitive workers 34

Table 3 Quest Drug Testing Index: General U.S. workforce 34

Table 4 Quest Drug Testing Index: Federally mandated safety-sensitive workers 34

Table 5 Quest Drug Testing Index: U.S. general workforce 35

Table 6 Serious marine incidents compared to all marine casualties 39

Table 7 Populations of commercial fishing vessels compared to small 42

 passenger vessels

Table 8 Initial and confirmatory drug test cutoff values 43

Table 9 CFV and SPV Post-Accident drug tests and results 51

Table 10 Yearly percentage differences between CFV and SPV positivity rates 53

Table 11 CFV and SPV Post-Accident drug test z scores with p values 54

Table 12 CFV and SPV Post-Accident alcohol tests and results 57

Table 13 Alcohol positivity rates of CFV crewmembers versus SPV crewmembers 58

 

Table 14 CFV and SPV Post-Accident alcohol test z scores with p values 59

Table 15 Post-Accident drug test positivity rates, commercial fishing vessels 62

 versus all vessels

Table 16 Percentage differences in CFV drug test positivity rates compared to all 64

 vessels

Table 17 CFV Post-Accident positive drug test rates compared to ALL vessels 65

 with z scores and p values

Table 18 Ratios of CFV and SPV Post-Accident positive drug tests per SMI 67
iv

Table 19 Percentage differences between CFV and SPV positive drug tests 68

 per SMI

Table 20 Ratios of CFV and SPV Post-Accident positive drug tests per SMI with 70

 z scores and p values

Table 21 Ratios of CFV and SPV Post-Accident positive alcohol tests per 72

 SMIs

Table 22 Percentage differences between CFV and SPV positive alcohol tests per 74

 SMI

Table 23 Ratios of CFV and SPV Post-Accident positive alcohol tests per SMI 75

 with z scores and p values

Table 24 MIS Pre-Employment, Random, and Post-Accident positivity rates 77

Table 25 Percentages of Crewmembers Randomly Tested 80
v

LIST OF FIGURES

Figure 1 Differences between CFV and SPV Post-Accident drug test positivity rates 52

Figure 2 Differences between CFV and SPV alcohol test positivity rates 58

Figure 3 Differences between CFV and ALL drug test positivity rates 63

Figure 4 Differences between CFV and SPV positive drug tests per SMI 68

Figure 5 Differences between CFV and SPV positive alcohol tests per SMI 73

Figure 6 MIS Pre-Employment, Random, and Post-Accident positivity rates 78

Figure 7 Trend Line of Random and Post-Accident positivity rates 79

Figure 8 Scatter Plot of Random and Post-Accident positivity rates 80

Figure 9 Scatter Plot and regression line for Random versus Post-Accident 82

 positivity rates
1

I. INTRODUCTION

A. OVERVIEW 

 The U.S. Coast Guard issues and enforces regulations to promote safety of life 

and property on and under the high seas and waters subject to the jurisdiction of the 

United States1 14 U.S.C. § 2 (2006). It also exercises general regulatory authority over 

the Merchant Marine, its vessels, and its personnel 46 U.S.C. § 2103 (2006). Pursuant to 

that authority, among others, the Coast Guard implemented chemical testing programs 

“to discourage drug and alcohol use by commercial vessel personnel, reduce the potential 

for marine casualties related to drug and alcohol use, and enhance the safety of the 

maritime transportation industry” Programs for Chemical Drug and Alcohol Testing of 

Commercial Vessel Personnel, 53 Fed. Reg. Nov. 21, 1988, p. 47,064. Title 46 U.S.C. § 

7702(c)(2) (2006) also mandates chemical testing commercial vessel personnel that are 

holders of Coast Guard issued Credentials for use of alcohol or dangerous drugs. 

B. CHEMICAL TESTING PROCESS

“Chemical testing means a scientifically recognized test which analyzes an 

individual’s breath, blood, urine, saliva, bodily fluids, or tissues for evidence of 

dangerous drug use” 46 C.F.R. § 16.105 (2012). “Dangerous drug means a narcotic 

drug, a controlled substance, or a controlled substance analog as defined in section 102 of 

 

1 The author is the Chief Administrative Law Judge for the U.S. Coast Guard, an agency of the U.S. 

Department of Homeland Security. Coast Guard Administrative Law Judges hear and decide cases 

Investigating Officers initiate to suspend or revoke Merchant Marine Credentials of commercial vessel 

personnel for misconduct, negligence, incompetence, violation of law or regulation, and drug use. Coast 

Guard Administrative Law Judges also hear and decide cases for other Homeland Security agency 

components as well as other agencies. The author’s opinions expressed herein are his own and do not 

reflect the views of the U.S. Department of Homeland Security, the Commandant of the Coast Guard, or 

the Office of Chief Administrative Law Judge, U.S. Coast Guard. 
2

the Comprehensive Drug Abuse and Control Act of 1970 (21 U.S.C. 820)” 46 C.F.R. § 

16.105 (2012). As used in this study, the term “drug test” is a test of an individual’s 

urine for evidence of dangerous drug use 49 C.F.R. pt. 40, subpts. C through F. The 

types of chemical testing include Pre-Employment, Periodic, Random, Reasonable 

Cause, and Post-Accident2 46 C.F.R. §§ 16.201-250 (2012). 

According to 46 C.F.R. § 4.06-15(a)(2)(2012), alcohol testing of commercial 

vessel personnel is performed with devices listed on either the Conforming Products List 

titled “Modal Specifications for Devices To Measure Breath Alcohol” or “Conforming 

Products List of Screening Devices To Measure Alcohol in Bodily Fluids.” For 

commercial vessel personnel, Post-Accident alcohol testing is ordered pursuant to 46 

C.F.R. §§ 16.240 and 16.500 (2012) for serious marine incidents and 33 C.F.R. § 

95.035(a)(1) (2012) when “[t]he individual was directly involved in the occurrence of a 

marine casualty as defined in Chapter 61 of Title 46, United States Code.” When 

comparing Post-Accident drug and alcohol test positivity rates between crewmembers 

subject to chemical testing and crewmembers not otherwise subject to chemical testing 

except for Post-Accident tests, this study focuses only on the positivity rates from serious 

marine incidents, not all marine casualties. 

As prescribed in 46 C.F.R. § 16.201(a) (2012), marine employers must initiate 

and conduct chemical testing as required by 46 C.F.R. pt. 16, subpt. B and in accordance 

with the procedures detailed in 49 C.F.R. pt. 40. With very few exceptions, marine 

employers of commercial fishing vessel crewmembers are exempt from initiating and 

 2 Employees previously testing positive must take Follow-Up and Return-To-Duty drug tests in accordance 

with 49 C.F.R. §§40.305 and 40.307 (2012). Those tests are not the subject of this study.
3

conducting chemical testing except for Post-Accident drugs and alcohol under 46 C.F.R. 

§ 16.240. Each urine specimen is chemically tested in accordance with the procedures in 

49 C.F.R. pt. 40 for the following dangerous drugs: marijuana, cocaine, opiates, 

phencyclidine (PCP); and amphetamines 46 C.F.R. § 16.103 (2012); 49 C.F.R. § 40.85 

(2012). The term “marine employer” means the owner, managing operator, charterer, 

agent, master, or person in charge of a vessel, other than a recreational vessel” 46 C.F.R. 

§ 16.105 (2012). Drug testing must be conducted by laboratories certified by the U.S. 

Department of Health and Human Services under the National Laboratory Certification 

Program for all testing conducted under 49 C.F.R. pt. 40 49 C.F.R. § 40.81(a) (2012). 

C. CONSEQUENCES OF FAILING A CHEMICAL TEST

The law as well as marine employers require certain commercial vessel 

crewmembers to hold Coast Guard issued Credentials.

3 Credentials determine and verify 

a crewmember’s qualifications and competencies to serve on merchant vessels. Under 46 

C.F.R. § 16.201(c) (2012), if an individual holding a Credential fails a chemical test, the 

employer, prospective employer, or sponsoring organization must report the test results in 

writing to the Coast Guard.4 The employer, prospective employer, or sponsoring 

organization must deny the individual employment as a crewmember or remove the 

individual from duties directly affecting the safe operation of the vessel as soon as 

practicable. Because chemical test results are reported to the Coast Guard, the individual 

 

3

The term “Credential” refers to Merchant Mariner’s Document, Merchant Mariner’s License, STCW 

Endorsement, and Certificate of Registry, as well as the Merchant Mariner’s Credential [46 C.F.R. § 16.105 

(2012)]. STCW Endorsement means the International Convention on Standards of Training, Certification 

and Watchkeeping for Seafarers, 1978, as amended 1995 46 C.F.R. §§ 10.101, 10.103(b) (2012). 

4 See also 46 U.S.C. § 7706 (2006) directing other federal agencies employing Credentialed crewmembers 

to forward test results to the Coast Guard. 
4

holder of a Coast Guard issued Credential failing the chemical test is also subject to 

suspension and revocation proceedings against his or her Credential in accordance with 

46 U.S.C. §§ 7701-7705 (2006), 46 C.F.R. pt. 5, and 33 C.F.R. pt. 20. The purpose of 

suspension and revocation proceedings is to promote safety at sea 46 U.S.C. § 7701(a) 

(2006). Those proceedings are remedial, not penal in nature and are intended to help 

maintain standards for competence and conduct essential for the promotion of safety at 

sea 46 C.F.R. § 5.5 (2012).

If the individual failing a chemical test for dangerous drugs does not hold a 

Credential, 46 C.F.R. § 16.201(d) (2012) requires marine employers to deny the 

individual employment as a crewmember or remove the individual from duties directly 

affecting the safe operation of the vessel as soon as possible. Under 46 C.F.R. § 

16.201(f) (2012), marine employers may not re-employ any individual described in 46 

C.F.R. §§ 16.201(c) and (d) aboard a vessel until the individual has completed the 

recommendations of the Substance Abuse Professional as described in 49 C.F.R. §§ 

40.281-313 (2012). Further, the Medical Review Officer (MRO) must determine the 

individual is drug-free and that the subsequent risk of drug use by that person is 

sufficiently low to justify a return to work. Moreover, the crewmember testing positive 

must agree to be subject to increased, unannounced testing for a minimum of six (6) tests 

in the first year after the crewmember returns to work as required in 49 CFR pt. 40 and 

for any additional period as determined by the Substance Abuse Professional or the MRO 

up to a total of 60 months. The first test is a Return-To-Duty test performed under direct 
5

observation. Subsequent to that test, Follow-Up tests are also performed under direct 

observation as ordered by the Substance Abuse professional or the MRO.5

 

If the Administrative Law Judge in suspension and revocation proceedings finds 

the positive chemical test was ordered in accordance with 46 C.F.R. pt. 16 and tested in 

accordance with the procedures in 49 C.F.R. pt. 40, the individual is presumed to be a 

user of dangerous drugs 46 C.F.R. §§ 16.201(a) and (b) (2012). Under 46 U.S.C. § 

7704(c) “[i]f it is shown that a [Credential] holder has been a user of, or addicted to, a 

dangerous drug, the license, certificate of registry, or merchant mariner's document 

(currently referred to as Credentials) shall be revoked unless the holder provides 

satisfactory proof that the holder is cured” (Emphasis and brackets added). The 

Administrative Law Judge must revoke the individual’s Credential unless the individual 

rebuts the presumption that he or she is a user of dangerous drugs or provides satisfactory 

proof of cure. 

D. CURE

Credentialed crewmembers testing positive are subject to having their credentials 

revoked in Coast Guard suspension and revocation proceedings. To provide satisfactory 

proof of cure, the current practice is for the crewmember/respondent to enter into a 

settlement agreement with the Coast Guard. This process allows the individual to deposit 

his or her Credential(s) with the Coast Guard pending successful completion of a 

recognized drug rehabilitation program followed by a one year period of remaining drug 

free, evidenced by passing 12 random, unannounced drug tests and attending prescribed 

 5 Interview with Mr. Robert C. Schoening, U.S. Coast Guard Drug and Alcohol Program Manager, August 

27, 2012. 
6

Narcotics Anonymous (NA) and/or Alcoholic Anonymous (AA) meetings. The Coast 

Guard will return the Credential(s) to the individual upon the following conditions: 

successfully completing drug rehabilitation (usually 2 months); remaining drug free for 

one year following drug rehabilitation as evidence by passing the prescribed, 

unannounced, random drug tests; attending NA/AA meetings as agreed upon; and,

obtaining clearance from the Substance Abuse Professional and the MRO that the 

individual is drug-free and the risk of subsequent dangerous drug use is sufficiently low 

to justify his or her return to work. During the period of Credential deposit, the 

individual is not permitted to work in any position requiring a Coast Guard issued 

Credential (Brudzinski, 2010, April 13). 

E. REQUIRED CHEMICAL TESTING 

Pre-Employment. An individual seeking employment as a crewmember in a 

position involving the safe operation of a vessel must pass a Pre-Employment chemical 

test for dangerous drugs as per 46 C.F.R. § 16.210(a) (2012). A marine employer may 

waive a Pre-Employment test if the individual provides satisfactory evidence of passing a 

chemical test for dangerous drugs required by 46 C.F.R. Part 16 within the previous six 

(6) months with no subsequent, positive drug tests during the remainder of the six month 

period; or, during the previous 185 days had been subject to a Random testing program 

required by 46 C.F.R §16.230 for at least 60 days and did not fail or refuse to participate 

in any chemical test required under 46 C.F.R. pt. 16 as per 46 C.F.R. § 16.210(b) (2012). 

After the potential crewmember passes the Pre-Employment drug test and is hired, that 

individual is further subject to unannounced Random tests, Reasonable Cause tests, and 

Post-Accident tests as per 46 C.F.R. pt.16, subpt. B (2012). 
7

Random. Title 46 C.F.R. § 16.230 (2012) requires marine employers to randomly 

drug test at least 50% of their crewmembers that work in safety-sensitive positions each 

year, performed at least once per quarter. For example, if the marine employer has 200 

covered employees subject to mandatory chemical testing, the marine employer must 

conduct at least 25 random tests each quarter of that year, for a total of 100 tests (.50 x 

200). Crewmembers previously selected in the first quarter’s test are also are subject to 

being selected for the next three quarters in the same fashion as those crewmembers not 

previously selected.6 The Coast Guard may adjust the 50% annual percentage rate 

downward to 25% of covered employees if the overall, yearly drug testing reports 

received from all employers show the Random positive rate to be less than 1% for two 

consecutive calendar years. Conversely, if the minimum annual percentage rate for 

Random drug testing is 25% and the drug testing reports from marine employers from the 

previous year indicate that the Random positive rate is equal to or greater than 1%, the 

Coast Guard will increase the minimum annual percentage rate for Random testing back 

to 50% for the following calendar year in accordance with 46 C.F.R. § 16.230 (2012).

 

6 Selecting crewmembers for Random testing is described in 46 C.F.R. § 16.230(c) (2012) as follows:

The selection of crewmembers for random drug testing shall be made by a scientifically 

valid method, such as a random number table or a computer-based random number 

generator that is matched with crewmembers' Social Security numbers, payroll 

identification numbers, or other comparable identifying numbers. Under the testing 

frequency and selection process used, each covered crewmember shall have an equal 

chance of being tested each time selections are made and an employee's chance of 

selection shall continue to exist throughout his or her employment. As an alternative, 

random selection may be accomplished by periodically selecting one or more vessels and 

testing all crewmembers covered by this section, provided that each vessel subject to the 

marine employer's test program remains equally subject to selection.
8

Periodic. Under 46 C.F.R. 16.220 (2012), the Coast Guard requires Periodic 

testing when it issues an initial Credential to a crewmember and any subsequent raise in 

grade, reissuance, or annual physical. As with Pre-Employment testing, the crewmember 

need not submit evidence of passing a chemical test for dangerous drugs if he or she 

provides satisfactory evidence of passing such a test as required by 46 C.F.R. pt. 16 

within the past previous six (6) months with no subsequent positive drug tests during the 

remainder of the six month period; or, during the previous 185 days had been subject to a 

Random testing program required by 46 C.F.R §16.230 (2012) for at least 60 days and 

did not fail or refuse to participate in any chemical test required under 46 C.F.R. pt. 16.

Reasonable Cause. Title 46 C.F.R. § 16.250 (2012) prescribes marine employers 

shall require any crewmember engaged or employed on board a vessel owned in the 

United States that is required by law or regulation to engage, employ, or be operated by 

an individual holding a Credential issued by the Coast Guard who is reasonably 

suspected of using a dangerous drug to undergo a chemical test for the use of dangerous 

drugs. “The employer’s suspicion must be based on a reasonable and articulable belief 

that the individual has used a dangerous drug based on direct observation of specific, 

contemporaneous, physical, behavioral, or performance indicators of probable use” as 

stated at 46 C.F.R. § 16.250(b) (2012). 

Post-Accident tests from serious marine incidents. Title 46 C.F.R. § 16.240 

(2012) requires marine employers to ensure all persons directly involved in a serious 

marine incident are chemically tested for evidence of dangerous drugs and alcohol in 

accordance with the requirements of 46 C.F.R. subpt. 4.06. A serious marine incident is 

defined in 46 C.F.R. § 4.03-2 (2012) and includes any incident described as a Marine 
9

Casualty or Accident in 46 C.F.R. 4.03-1 (2012) for which the owner, agent, master, 

operator, or person in charge shall notify the Coast Guard in accordance with 46 C.F.R. § 

4.05.1 (2012).

7

 Serious Marine Incidents include one or more deaths; any injury to a 

crewmember, passenger, or other person which requires professional medical treatment 

beyond first aid; damage to property in excess of $100,000; actual or constructive loss of 

a vessel; a discharge of 10,000 gallons or more of oil into the navigable waters of the 

United States; and, discharges of a reportable quantity of hazardous substance into the 

environment or navigable waters of the United States. 

Under 46 C.F.R. § 4.05-1 (2012) the Coast Guard must be notified of the 

following: an unintended grounding, or an unintended strike of (allusion with) a bridge; 

an intended grounding or an intended strike of a bridge that creates a hazard to 

navigation, the environment, or the safety of a vessel; a loss of main propulsion, steering, 

or any associated component or control system that reduces the maneuverability of the 

vessel; an occurrence that adversely affects the vessel’s seaworthiness including fire or 

flooding; loss of life; injury requiring professional medical treatment beyond first aid; 

property damage in excess of $25,000; and, an occurrence involving significant harm to 

the environment. 

Title 46 C.F.R. § 4.06-1(b) (2012) prescribes once a marine employer determines 

a casualty or incident is or is likely to become a serious marine incident, the marine 

 7 Ordinary Marine Casualties or Accidents defined in section 4.03-1 generally include any fall overboard, 

injury, or loss of life of any person and any occurrence involving a vessel that results in grounding, 

stranding, foundering, flooding, collision, allusion, explosion, fire, reduction or loss of a vessel’s electrical 

power, propulsion, or steering capabilities. Marine Casualties or Accidents also include failures that impair 

any aspect of a vessel’s operation; any other circumstances that might affect or impair a vessel’s 

seaworthiness, efficiency, or fitness for service or route; and, any incident involving significant harm to the 

environment, among other things. 
10

employer shall take all practicable steps to have each crewmember on board the vessel

who is directly involved in the incident chemically tested for evidence of drug and 

alcohol use. Alcohol testing must occur within two hours of the serious marine incident, 

if practicable; drug testing must occur within 32 hours of the serious marine incident 46 

C.F.R. § 4.06-3 (2012).

F. RECORDS AND REPORTS 

In addition to the immediate notice required in section 4.05-1, the owner, agent, 

master, operator, or person in charge must prepare written report of any marine casualty 

required to be reported under § 4.05–1 within five days of the incident. This written 

report must be delivered to a Coast Guard Sector Office or Marine Inspection Office. It 

must be provided on Form CG-2692 (Report of Marine Accident, Injury or Death), 

supplemented as necessary by appended Forms CG-2692A (Barge Addendum) and CG2692B (Report of Required Chemical Drug and Alcohol Testing Following a Serious 

Marine Incident) 46 C.F.R. 4.05-10(a) (2012). This is how the Coast Guard obtains PostAccident chemical testing results from serious marine incidents in accordance with 46 

C.F.R. § 4.06-3 (2012). 

Marine employers are also required to maintain records of chemical tests and 

make those records available to the Coast Guard upon request 46 C.F.R § 16.260 (2012). 

Further, marine employers must submit yearly drug testing data and results on the U.S. 

Department of Transportation Drug and Alcohol Testing Management Information 

System (MIS) Data Collection Form to Commandant, (CG–INV), U.S. Coast Guard, 

2100 2nd St. SW., Stop 7581, Washington, DC 20593–7581 46 C.F.R. §16.500 (2012); 

49 C.F.R. pt. 40, Appendix H. The provisions in 49 C.F.R. pt. 40 for alcohol testing by 
11

Department of Transportation (DOT) agencies do not apply to the Coast Guard or to 

marine employers. Marine employers are not required or permitted to submit alcohol 

testing data other than in accordance with the requirements of 46 C.F.R. § 4.06 (2012) for 

Serious Marine Incident reports as per 46 C.F.R. § 16.500(a)(2) (2012). Marine 

employers submit alcohol testing results on the Report of Required Chemical Drug and 

Alcohol Testing Following a Serious Marine Incident which supplements the Report of 

Marine Accident, Injury or Death, CG-2692B.8

G. EMPLOYEE ASSISTANCE PROGRAMS 

Crewmembers are aware that a positive chemical test has serious consequences 

from loss of their employment to loss of their Coast Guard issued Credentials. Their 

employers make them aware through the company’s policy and the Coast Guard makes 

those with Credentials aware during their licensing process. Yet, significant numbers of 

crewmembers still test positive, lose their employment, and, if they are Credential 

holders, are subject to suspension and revocation proceedings typically resulting in the 

loss of their Credentials unless they provide satisfactory proof that they are cured of 

dangerous drug use. 

To assist crewmembers in avoiding dangerous drug use, the Coast Guard also 

requires marine employers to provide Employee Assistance Programs (EAP) for all 

crewmembers. Each EAP must include education and training on drug use for both 

crewmembers and supervisory personnel. The EAP must: 1) display and distribute

informational material; 2) display and distribute a community service hot-line telephone 

 8 Under 46 C.F.R. §§ 4.06-70 and 16.115 (2012), marine employers failing to implement, conduct or 

comply with chemical testing requirements are subject to civil penalties.
12

number for crewmember assistance; and, 3) display and distribute the employer's policy 

regarding drug and alcohol use in the workplace 46 C.F.R. 16.401 (2012). 

H. PURPOSE 

As stated in the Final Rule, chemical testing’s goals are “to discourage drug and 

alcohol use by commercial vessel personnel, reduce the potential for marine casualties 

related to drug and alcohol use, and enhance the safety of the maritime transportation

industry.” 

Federally mandated chemical testing of commercial vessel personnel substantially 

impacts crewmembers as well as marine employers; however, its effects on discouraging 

drug and alcohol use, reducing the potential for marine casualties related to drug and 

alcohol use, and enhancing the safety of the maritime transportation have not been the 

subject of empirical study and to that extent remain largely unknown. Determining the 

extent chemical testing is discouraging drug and alcohol use, reducing the potential for

marine casualties, and enhancing the safety of the maritime transportation industry is 

therefore appropriate for inquiry and is this study’s purpose. 

I. RESEARCH QUESTIONS AND HYPOTHESES

Research question number 1: To what extent, if any, has chemical testing 

discouraged drug and alcohol use by commercial vessel personnel? The following 

Hypotheses address that research question:

Hypothesis 1A: Yearly 2003-2011 Post-Accident drug test positivity rates from 

small passenger vessel crewmembers subject to chemical testing are significantly lower 

than yearly 2003-2011 Post-Accident drug test positivity rates from commercial fishing 

vessel crewmembers not otherwise subject to chemical testing. 
13

Hypothesis 1B: Yearly 2003-2011 Post-Accident alcohol test positivity rates 

from small passenger vessel crewmembers subject to chemical testing are significantly 

lower than yearly 2003-2011 Post-Accident alcohol test positivity rates from commercial 

fishing vessel crewmembers not otherwise subject to chemical testing. 

Hypothesis 1C: Yearly 2003-2011 Post-Accident drug test positivity rates from 

all crewmembers subject to chemical testing from all vessels are significantly lower than 

yearly 2003-2011 Post-Accident drug test positivity rates from commercial fishing vessel 

crewmembers not otherwise subject to chemical testing. 

Research question number 2: To what extent, if any, does chemical testing reduce 

the potential for marine casualties related to drug and alcohol use? The following 

Hypotheses address that research question:

Hypothesis 2A: The yearly 2003-2011 ratios of Post-Accident positive drug tests 

per serious marine incident from small passenger vessel crewmembers subject to 

chemical testing are significantly lower than corresponding Post-Accident positive drug 

tests per serious marine incident from commercial fishing vessel crewmembers not 

otherwise subject to chemical testing.

Hypothesis 2B: The yearly 2003-2011 ratios of Post-Accident positive alcohol 

tests per serious marine incident from small passenger vessel crewmembers subject to 

chemical testing are significantly lower than corresponding Post-Accident positive 

alcohol tests per serious marine incident from commercial fishing vessel crewmembers 

not otherwise subject to chemical testing. 
14

Research question number 3: To what extent, if any, does chemical testing 

enhance the safety of the maritime transportation industry? The following Hypothesis 

addresses that research question: 

Hypothesis 3: Yearly 2003-2011 Post-Accident drug test positivity rates from all 

vessels with crewmembers subject to chemical testing will correlate positively and 

strongly with decreasingly lower Random drug test positivity rates from 2003-2011 for

all vessels with crewmembers subject to chemical testing. 

This study assumes the data reported to the Coast Guard was accurate; that small 

passenger vessel crewmembers have passed a Pre-Employment chemical prior to being 

hired and are aware they are still subject to Random, Reasonable-Cause, and PostAccident chemical tests for drugs and alcohol; that commercial fishing vessel 

crewmembers are not subject to chemical tests except Post-Accident drugs and alcohol 

and may not be aware they are subject to Post-Accident chemical tests. 
15

II. LITERATURE REVIEW

A. OVERVIEW

There are no empirical studies specifically concerning chemical testing of 

commercial vessel personnel. This might be attributed in part to the overall 

comprehensiveness of the regulations as described above; the “zero tolerance” sanctions 

for those crewmembers testing positive; and, the opportunities available to crewmembers 

to demonstrate they are cured of drug use so they can return to work. The lack of 

empirical studies on commercial vessel personnel chemical testing is not surprising 

because it is consistent with the relative dearth of empirical studies in transportation and 

workplace drug testing in general, especially in the last five years. This may be due in 

part to the difficulty in attributing drug testing directly to those areas it seeks to improve, 

such as work performance and safety. As shown in the literature review, empirical 

studies to measure drug testing’s effect on work performance and safety have met with 

mixed results, not because drug use has no effects on work performance or safety, but 

because of the methods used. Instead of attempting to measure specific areas of work 

performance or safety, this study measured the goals of federally mandated chemical 

testing as expressed in the final rule. 

The Literature Review begins with a brief discussion of the reasons for 

implementing chemical testing followed by brief discussions of articles pertaining to the 

suspension and revocation process against credentialed crewmembers/mariners that test 

positive for dangerous drugs.9

 The “zero tolerance” nature of the suspension and 

revocation process is perhaps the major factor in discouraging drug use. The Literature 

 9 For the purpose of this study, the terms “crewmember(s)” and “mariner(s)” are used interchangeably.
16

Review also acknowledges the constitutional issues surrounding mandatory drug testing. 

This study does not evaluate the suspension and revocation process nor does it discuss the 

constitutional aspects of mandatory drug testing; however, having a familiarity with these 

aspects is helpful in understanding the expressed goals of federally mandated chemical 

testing. It is also helpful to show the need for more empirical work on testing results. 

The Literature Review then discusses articles on drug testing’s limitations

followed by discussions of articles on discouraging drug use, drug testing and accidents, 

and Quest Diagnostics’ Drug Testing Index. It ends with a brief discussion of the most 

practical methods to evaluate federally-mandated chemical testing of commercial vessel 

personnel which leads to the methods employed in this study. 

B. BACKGROUND

The Coast Guard initially expressed its reasons for implementing chemical testing 

in the Summary section of its Notice of Proposed Rulemaking as follows: “Through 

chemical testing, the Coast Guard expects to discourage drug and alcohol use by 

merchant marine personnel, an activity which adversely impacts the users, their 

shipmates, the marine industry, and the public in general. Chemical testing should also 

reduce the potential for marine casualties related to drug and alcohol use” (proposed, 53 

Fed. Reg. Jun. 8, 1988, p. 25,926). The Summary section of the Final Rule, entitled 

“Programs for Chemical Drug and Alcohol Testing of Commercial Vessel Personnel”

further articulated those reasons as follows:

These regulations require the establishment of anti-drug programs to 

reduce the incidence of drug abuse by commercial vessel personnel. These 

programs include pre-employment, periodic, random, post-accident and 

reasonable cause testing. The post-accident portion of the program also 

involves testing for alcohol use. The Coast Guard believes these rules will 
17

discourage drug and alcohol use by commercial vessel personnel, reduce 

the potential for marine casualties related to drug and alcohol use, and 

enhance the safety of the maritime transportation industry (Programs for 

Chemical Drug and Alcohol Testing of Commercial Vessel Personnel, 53 

Fed. Reg. Nov. 21, 1988, p. 47,064).

10

Shortly after the Coast Guard implemented chemical testing, one law review 

article entitled “Drug and Alcohol Testing of Maritime Personnel” addressed the 

constitutionality of on-the-job drug testing (Wright, 1989). The Wright article discusses 

the regulations in light of the Supreme Court’s decisions in Skinner v. Railway Labor 

Executives Association, 409 U.S. 602 (1989) (warrant not required for safety sensitive 

positions) and National Treasury Employees Union v. Von Raab, 409 U.S. 656 (1989) 

(drug testing must be reasonable). In both cases, the Supreme Court of the United States 

found mandatory drug testing did not violate the Fourth Amendment because the 

Government had a compelling interest in ensuring public safety. Wright analyzes those 

decisions and discusses the likely impact on Coast Guard regulations mandating chemical 

testing of commercial vessel personnel. 

Wright finds the regulations at 46 C.F.R. pt. 16 are probably constitutional 

because little or no discretion is permitted in implementing them. The scope of 

permissible testing is well defined; however, he finds the privacy interests of maritime 

employees are severely infringed upon which would tend not to support the regulations’ 

constitutionality. But, Wright recognizes the maritime industry has always been highly 

 10 In 1988, the Coast Guard was part of the U.S. Department of Transportation. The Coast Guard became 

part of the U.S. Department of Homeland Security pursuant to § 888 of “The Homeland Security Act of 

2002,” Pub. L. 107-296, 116 Stat. 2135, 2249 (Nov. 25, 2002). Implementing chemical testing was done in 

concert with other Department of Transportation modal agencies. See the Department of Transportation’s 

Office of Drug and Alcohol Policy and Compliance website at http://www.dot.gov/odapc/oamanagers.html. 
18

regulated and that these regulations narrowly define the types of drugs to be tested for, 

the circumstances under which the tests may be performed, and who may perform them. 

Most importantly, Wright recognizes that the Government’s interest in 

maintaining safety in the maritime industry is very significant and that “it will be up to a 

federal judge or perhaps the Supreme Court to make a policy decision regarding whose 

interest is more important – that of the Government in maintaining safety in the maritime 

industry, or that of the employees in maintaining their privacy” (Wright, 1989, pp. 556-

57). The constitutional aspects of federally mandated drug testing have survived many 

constitutional tests so it appears testing commercial vessel personnel in accordance with 

the procedures described above are here to stay. 

Concerning what happens to test results after marine employers forward them to 

the Coast Guard, only three articles appeared in the literature pertaining to federallymandated chemical testing of commercial vessel personnel. The first article concerns 

those crewmembers holding Coast Guard Credentials and testing positive for dangerous 

drugs. It provides guidance to maritime attorneys representing those mariners in 

administrative hearings (Spivey, 1997). Spivey discusses the circumstances under which 

crewmembers are required to be tested for dangerous drugs, the testing process, and the 

method by which the Coast Guard issues formal charges if the drug test result is positive. 

She also covers procedures in lieu of an administrative hearing such as voluntary deposit,

or voluntary surrender in lieu of a hearing that relinquishes the Credential permanently. 

Finally, she discusses the administrative hearing process, the Administrative Law Judge’s 

role, and appeal procedures. Although the procedural rules have changed in the last 15 

years, this article is still an excellent primer on the suspension and revocation process 
19

involving crewmembers facing loss of their Credentials as the result of a positive 

chemical test for dangerous drugs. 

This author also published an article addressing similar issues covered in the 

Spivey article but with new information based on regulatory changes and recent appeal 

decisions concerning the cure process (Brudzinski, 2010, April 13). The latter article 

places particular emphasis on the options available to mariners that test positive for 

dangerous drugs which enable them to have their Credentials returned. It addresses the 

hearing process but also details procedures for entering into and successfully completing 

the terms of a cure settlement agreement, an avenue chosen by most credentialed 

mariners/crewmembers that test positive. The suspension and revocation process allows 

for little discretion on the part of the Administrative Law Judge if the Judge finds the 

reason for the test is in accordance with 46 C.F.R. pt. 16 and the sample was tested in 

accordance with 49 C.F.R. pt. 40. If the chemical test is ordered in accordance with 46 

C.F.R. pt. 16, a positive result creates the presumption that the crewmember is a user of 

dangerous drugs for which is the law mandates Revocation of the crewmember’s 

Credential (Brudzinski, 2011); 46 U.S.C. § 7704(c) (2006). The above articles provide a 

thorough overview of the Coast Guard’s suspension and revocation process involving 

credentialed mariners that test positive for dangerous drugs; however, the articles do not 

provide any empirical evidence that chemical testing discourages drug use, reduces the 

potential for casualties related to drug and alcohol use, and enhances the safety of 

maritime transportation. 
20

C. DRUG TESTING’S LIMITATIONS

Rothstein (1991) claims there are several problems with drug testing from the 

standpoint of technology assessment: 1) misidentification can occur because drug tests 

detect metabolites rather than the drugs themselves (chemical tests under 49 C.F.R. pt. 40 

detects both); 2) metabolites do not detect impairment (except through the blood 

immediately, then it shows in the urine); 3) the duration of detectability of drug 

metabolites in urine is limited; and, 4) there may be positives due to passive inhalation 

(however, the cut off levels in 49 C.F.R. pt. 40 are high enough to disprove this). Despite 

these limitations, one may infer people that test positive are more likely than those who 

test negative to come to work under the influence of drugs or take drugs during the 

workday. In general, Rothstein claims drug testing’s goal was not clear and its 

effectiveness was unproven (Rothstein, 1991). These are all valid concerns and 

improvements over the last two decades have minimized many of them; however, 

federally-mandated chemical testing of commercial vessel personnel’s goals are clear: 1) 

discourage drug and alcohol use among commercial vessel personnel; 2) reduce the 

potential for marine casualties related to drug and alcohol use; and, 3) enhance the safety 

of maritime transportation industry. 

Drug testing’s proponents claim improved productivity and safety with fewer 

drug related absences and accidents are being directly attributed to drug testing but even 

if these improvements resulted from drug testing, it is not clear that they would not have 

occurred in the absence of drug testing (Rothstein, 1991). Agreed, but “Coast Guard data 

do not specifically indentify the use of drugs or alcohol as a major causal effect in 

commercial vessel losses or casualty damage” (proposed, 53 Fed. Reg. Jul. 8, 1988, p. 
21

25,927). Accordingly, this study does not examine the relationship between chemical 

testing and the number or frequency of accidents, personal injuries, or deaths because 

increases or decreases in injuries or deaths may be due to factors other than use of 

dangerous drugs. Reducing the potential for marine casualties related to drug and alcohol 

use does not require findings that drugs or alcohol caused the casualty. 

A few years later, Comer (1994) claimed, among other things, that drug testing 

has not been shown to be associated with enhanced organizational productivity and 

safety. Comer cites Normand, Salyards, and Mahoney (1990) who studied applicants for 

postal service jobs in Washington, D.C. Those applicants tested positive for drugs but 

were hired for the purposes of data collection. The hired applicants had higher rates of 

absenteeism and involuntary turnover but there was no significant relationship between 

their Pre-Employment drug test results and their rate of injuries and accidents (Comer, 

1994). These findings are similar to those in Parish (1989) concerning drug testing and 

job performance. Parish (1989) conducted a six month examination of 180 new 

employees at a large teaching hospital. Urine testing resulted in a 12% positivity rate. 

Parish (1989) found no significant differences between employees testing positive and 

those testing negative because the size of the drug-positive groups was not large enough 

to detect subtle differences in job performance or retention and that further study is 

needed. These findings seem to be consistent with the observations of Rothstein (1991) 

and Comer (1994). The Coast Guard did not attempt to claim chemical testing would 

improve job performance, productivity, or overall safety. It claimed chemical testing 

“should also reduce the potential for marine casualties related to drug and alcohol use”

(proposed, 53 Fed. Reg. Jul. 8, 1988, p. 25,927). In its Final Rule, it expanded that
22

statement to “reduce the potential for marine casualties related to drug and alcohol use, 

and enhance the safety of the maritime transportation industry” (53 Fed. Reg. Nov. 21, 

1988, p. 47,064). 

D. DISCOURAGING DRUG USE IN GENERAL

It makes sense that the first step any employer would take to discourage drug use 

would be to screen employment applicants for evidence of drug use.

11 To determine the 

effectiveness of drug screening applicants, Cabanilla, Frankenfield, Fudala, Lange, and 

Moler (1994) conducted a two month study in 1989 and again in 1991, screening 

applicants for employment at the Johns Hopkins Hospital in Baltimore, Maryland. 

Among other things, they found 10.8% of acceptable urine specimens tested positive for 

one or more drugs in 1989 versus 5.8% in 1991. They also found the decrease to be 

statistically significant (p < 0.05). The authors acknowledge that the rate of drug use 

within society had also decreased from 1989 to 1991; however, they claim the decrease in 

their study was more dramatic and appears to reflect other forces rendering it unlikely to 

be due to shifting drug use patterns within the community where their applicants were 

drawn. 

Cabanilla et al. (1994) conclude the decrease in drug detection among applicants 

for employment was related, at least in part, to the existence of the urine testing program. 

The United States Coast Guard implemented chemical testing to discourage drug and 

alcohol use by commercial vessel personnel, reduce the potential for marine casualties 

related to drug and alcohol use, and enhance the safety of the maritime transportation

industry. Similar to Cabanill et al. (1994) the study described herein examines the extent 

 11 The terms “discourage” and “deter” are used interchangeably in this study. 
23

to which chemical testing has discouraged drug and alcohol use by commercial vessel 

personnel. A good starting point to determine whether drug testing discourages drug use 

among commercial vessel crewmembers is the military. The military has been drug 

testing its personnel since 1981. Like chemical testing of commercial vessel personnel, 

the military imposes job loss on those who test positive and such high penalties are likely 

to yield the maximum deterrence (Mehay & Pacula, 1999). 

Using 1995 data from the National Household Survey of Drug Abuse (NHSDA) 

and the Department of Defense’s Worldwide Survey of Drug Abuse (DODWWS), 

Mehay and Pacula (1999) examined the deterrence effect by comparing differences in 

illicit drug use between the military and the civilian populations.12 They found the 

military’s strict anti-drug program to be highly effective in deterring illicit drug use to the 

extent drug participation in the military ranged between 4% and 16% lower than in the 

civilian sector, depending on the age group. They also used surveys based on selfreported data, which by their very nature may be subject to biases or underreporting. 

Mehay and Pacula (1999) suggest costs savings and deterrence through lower 

random testing rates might be better achieved by returning to the “two-strikes policy” 

used in 1984 (allowing lower ranking members to remain in the service after a positive 

drug test) rather than terminating all personnel and replacing them as a result of one 

positive test13 (Mehay & Pacula, 1999). 

 12 The National Household Survey on Drug Abuse (NHSDA) is now called the National Survey on Drug 

Use and Health (NSDUH). Source - http://www.oas.samhsa.gov/NSDUHlatest.htm. 

13 The survey questionnaire asks “if the military stopped random, unannounced drug testing, how likely do 

you think you would be to use drugs” but does not discuss the percentage breakdown in responses. 

DODWWS, (2008), Appendix J, p.16, question 94.
24

According to the 2008 DOD Survey of Health Related Behaviors Among Active 

Duty Military, self-reported dangerous drug use within the last 30 days in the military 

decreased from 27.6% in 1980 to 19.0% in 1982, 8.9% in 1985, 4.5% in 1988, 3.4% in 

1992, 3.0% in 1995, 2.7% in 1998, and 3.4% in 2002. In 2005 and 2008 it increased to 

5.0% and 12.0% respectively due in part to wording changes in the questionnaires; 

therefore, percentages from those years are not comparable to prior years (DOD Survey, 

2008, Table 3.2.2). Self-reported heavy alcohol use (consuming five or more drinks on 

the same occasion at least once a week during the past 30 days) within the past month has 

remained at about the same level (20 to 21%), except between 1988 and 2005 when it fell 

to 15-18.5% (DOD Survey, 2008, Table 3.2.1; Executive Summary, p. 3). 

Mehay and Pacula’s (1999) concern about the cost of replacing terminated 

personnel is valid because commercial vessel personnel that test positive lose their jobs 

as well. If they are holders of Coast Guard issued Credentials, they also are subject to 

losing their Credentials through the suspension and revocation process; however, they 

may avail themselves of the opportunities for cure as detailed at 46 C.F.R. §§16.201(e) 

and (f) so they can return to work; and, if they are Credential holders, the additional 

requirements prescribed in their settlement agreements. The individual crewmember, 

however, must bear the cost of cure. Unlike Mehay and Pacula (1999), this study did not 

use surveys; instead, it used drug testing results reported to the Coast Guard by marine 

employers. 

French, Roebuck, and Alexandre (2004) found, among other things, 47% of those 

surveyed worked for a company that had some type of drug testing program, the most 

popular of which was pre-employment testing (38.8%) followed by reasonable suspicion 
25

testing (30.6%), then random testing (24.2%). The study used data from the 1997 and 

1998 National Household Surveys on Drug Abuse to examine the relationships among 

drug use and workplace drug testing programs for employed individuals between age 18 

and 65. They found those programs achieved a desirable result by deterring some 

potential drug using employees but it often comes at a high cost in the form of drug 

testing expenses, employee turnover, and additional recruitment efforts, similar to the 

findings in the Mehay and Pacula (1999) study. 

Mehay and Pacula (1999) as well as French et al. (2004) suggest drug testing 

seems to discourage drug use but questions whether the costs are worth it. The costs of 

chemical testing commercial vessel personnel (approximately $50 - $65 per test, 

depending on the type) are dispersed among individual commercial vessel personnel and 

their employers. These costs can be kept low by fewer positive Random tests which will 

result in overall Random testing at the 25% level instead of the 50% level. Fewer 

positive chemical tests will ordinarily result in a decreased need for additional chemical 

tests which necessarily drive up the costs. Further, less drug use will ordinarily result in 

fewer Reasonable Cause tests and fewer Post-Accident tests.

E. DISCOURAGING STUDENT DRUG USE

On the issue of simply discouraging drug use, studies pertaining to students are 

informative. James-Burdumy, Goesling, Deke, and Einspruch (2010) studied mandatoryrandom student drug testing (MRSDT). MRSDT’s goal is to reduce substance use among 

students whose high school districts have applied for and received funds to implement 

mandatory-random drug testing. MRSDT requires students and their parents to sign 

consent forms agreeing that participation in sports or other school activities will be
26

conditioned upon the students being subject to random drug testing. Like commercial 

vessel personnel chemical testing, the MRSDT program administers drug tests to at least 

50% of eligible students to detect the presence of at least five substances (marijuana, 

amphetamines, cocaine, methamphetamines, and opiates). MRSDT also uses 

questionnaires concerning alcohol use. 

The MRSDT program’s theory predicts mandatory, random student drug testing 

may reduce students’ use of substances. If students are aware a random drug test is 

possible they might stop using substances or at least give them a reason to refuse to use 

substances. The program also predicted students testing positive for drugs can be 

identified and referred for treatment or counseling. Finally, the MRSDT program 

predicted it would most likely have a “spillover” effect on other students as they observe 

and are influenced by their peers’ behavior. 

James-Burdumy et al. (2010) compared students in treatment schools with 

MRSDT to students in control schools without MRSDT. Among other things, the study 

discovered that within the preceding thirty days, 16% of students subject to MRSDT 

reported using any substance compared with 22 % of comparable students in the control 

schools without MRSDT. It also found 10 % of students subject to MRSDT reported 

using any substance excluding alcohol within the preceding thirty days compared to 13% 

of comparable students in the control schools without MRSDT. Further, it found testing 

for a larger number of substances as well as testing for alcohol and tobacco were 

significantly correlated with lower substance use in the treatment schools relative to the 

control schools. Out of 3,476 random drug tests administered in MRSDT schools during 

the year long, 2007-2008 evaluation period, 38 were positive, resulting in a drug test positive 
27

rate of 1.09%. The study also found a decline in student drug use over the last 10 years. 

This study of commercial vessel personnel shows similar results from archived drug 

testing results, not from questionnaires. For example, the Random positive test rate for 

commercial vessel personnel during 2007-2008 averaged 1.15%, close to the MRST 

positive rate of 1.09%. MRST students and commercial vessel crewmembers were aware 

that they were subject to unannounced random drug testing. 

The MRST study found no “spillover effect” from experimental schools to control 

schools and no impact on the number of disciplinary incidents. Like the MRSDT program’s 

theory that drug testing reduces student substance use in part by deterrence through the threat 

of testing, this study shows mandatory chemical testing of commercial vessel personnel 

coincides with reduced substance use, including alcohol. 

There are two other studies pertaining to student drug testing that have relevance to 

discouraging drug use by commercial vessel personnel. The first study is by Yamaguchi, 

Johnston, and O’Malley (2003a). The authors used questionnaires and focused on grades 

8, 10, and 12. Among other research questions, Yamaguchi et al., 2003a, p. 159 asked: 

“What relationship exists between student drug use and school testing?” The 

investigators found no association between drug testing and the prevalence or frequency 

of student drug use (Yamaguchi et al., 2003a).

The same authors conducted a subsequent study, referred to as Yamagouchi et al., 

(2003b). Their second study found drug testing does not inhibit student drug use but 

random testing of all students was the most promising in reducing student drug use. It 

also found testing of athletes did not produce encouraging results (Yamagouchi et al. 

2003b). Consistent with these findings, the study of commercial vessel crewmembers 
28

shows, among other things, that gradually decreasing Random drug test positivity rates 

are an accurate predictor of gradually decreasing Post-Accident positivity rates. 

F. DRUG TESTING AND ACCIDENTS

In the construction industry, with its high rates of alcohol and other drug use 

coupled with the high-risk, safety-sensitive nature of the work, Gerber and Yacoubian 

(2001) found that between 1988 and 1998, the average company in its questionnaire 

sample that tested for drugs reduced its injury rate 51% within two years of implementing 

drug testing. The sample’s injury rate went from 8.9 injuries per 200,000 work-hours to 

4.4 injuries per 200,000 work-hours, which was statistically significant (Gerber & 

Yacoubian, 2001). 

Even if the improvements noted in the Gerber and Yacoubian (2001) study 

resulted from drug testing, they could have taken place in the absence of drug testing 

(Rothstein, 1991). The same can be said for vessel casualties, injuries, and deaths. 

Crewmember injuries and deaths as well as vessel losses and damages may be higher or 

lower but the reasons may not necessarily be due to chemical testing or the absence of 

chemical testing. For example, from 1992 through 2010, there were 2,072 fishing vessels 

lost at sea and 1,055 fishing vessel fatalities. The fishing vessel losses averaged 109 per 

year but from 2006 through 2010, the average loss rate dropped to 61 per year. The 

fatalities averaged 56 per year but from 2006 through 2010, the average dropped to 39 per 

year (U.S. Coast Guard, 2011). Most losses are due to flooding and fires - problems that 

are largely not covered nor can be substantially prevented by the current regulations.

The reductions in fishing vessel losses and fatalities cannot be attributed to PreEmployment, Random, or Reasonable-Cause drug testing because commercial fishing 
29

vessel crewmembers are not subject to those comprehensive chemical tests except for 

Post-Accident drug and alcohol tests. In the case of crewmembers on other vessels 

subject to comprehensive chemical testing, the potential for marine casualties related to 

drugs or alcohol may decrease but it does not necessarily mean that the potential for 

marine casualties related to non-drug or non-alcohol factors will also decrease. Put 

another way, while the number of vessel casualties related to drugs and alcohol 

decreases, the number of vessel casualties related to other factors may increase. 

Jacobson (2003) found from 1988 through 1990, drug testing led to a 9 to 10 

percent reduction in truck accident fatalities but she does not “reject at the 5 percent level 

the hypothesis that there has been no change in trends in fatal truck crashes relative to car 

crashes per VMT [vehicle miles traveled] in 1998, 1989, or 1990” (Jacobson, 2003, 

p.139). Put another way, the reduction in truck accident fatalities may not necessarily be 

attributed to drug testing compared to car crash fatalities per vehicle miles traveled. The 

Jacobson study illustrates the limitations in attempting to link drug testing with improved 

safety statistics. Relating the Jacobson study to chemical testing of commercial vessel 

personnel, marine casualty data might show vessels with crewmembers not subject to 

chemical testing other than Post-Accident drug and alcohol testing have a higher death 

rate per serious marine incident than vessels with crewmembers previously subject to 

Random drug testing. To claim chemical testing reduces the number of deaths per 

serious marine incident would ignore the multitude of other causative factors such as 

crew training and certification, material condition of the vessel, the relative danger of the 

vessel’s work, duration and conditions of deployment, and crew fatigue, just to name a 

few. Because of those limitations, this study addressed only the goals of commercial 
30

vessel personnel chemical testing as expressed in the Final Rule and avoided any 

comparisons of death or injury rates. 

Normand et al. (1990) investigated the relationship between pre-employment 

drug-test results and absenteeism, turnover, injury, and accidents of U.S. Postal Service 

employees. Among other things, the Normand study found the positive drug-test group 

had a 59.3% higher absence rate and a 47% higher involuntary separation rate than those 

who tested negative. However, Normand et al. (1990) found no statistically significant 

relationship between drug-test results and the number of injuries and no statistically 

significant relationship between drug-test results and the number of accidents. The study 

explained that various factors may have contributed to the non-significant findings such 

as the relatively short amount of time new employees were studied and the relatively low 

numbers of employees. “As the tenure of participants increases, the accident and injury 

rates are expected to increase, which will permit us to more efficiently detect any true 

differences” (Normand et al., 1990, p. 637). 

Zwerling, Ryan, and Orav (1990) conducted pre-employment drug screening of 

U.S. Postal Service employees that were hired and found those testing positive for 

marijuana had increased risks of termination, accident, injuries, and discipline compared 

to those testing negative. More specifically, Zwerling et al. (1990) found those testing 

positive for marijuana have 55% more industrial accidents, 85% more injuries, and a 78% 

increase in absenteeism. Zwerling et al. (1990) also found those testing positive for 

cocaine had no increased risk for termination but did have an increased risk for accidents, 

injuries, and disciplinary actions relative to those testing negative; however, only the risk 

for injuries was statistically significant for those testing positive for cocaine. Those 
31

testing positive for cocaine had a 145% increase in absenteeism and also an 85% increase 

in injuries (Zwerling et al., 1990). 

In their second Post Office study, Ryan, Zwerling, and Jones (1992) found those 

that tested positive for marijuana and cocaine had increased risks for firing, accidents, 

injuries, discipline, and absence. Ryan et al. (1992) specifically found marijuana users 

had a statically significant increased risk of accident and injury and that cocaine users had 

a statistically significant increased risk of accident but just short of a statistically 

significant risk for injury ( p = .051). 

Consistent with Normand et al. (1990) and somewhat at odds with Zwerling et al. 

(1990) and Ryan et al. (1992) is Parish (1989). Parish assessed the relationship between 

positive drug tests and job performance. He compared job performance characteristics 

of employees testing positive with those employees testing negative and found “no 

significant difference between individuals who tested positive and those who tested 

negative using broad categories of job performance” (Parish, 1989, p. 47). 

The instant study on commercial vessel crewmembers focused on Random and 

Post-Accident positivity rates with the latter category including injuries and accidents. It 

did not address job performance because prospective crewmembers that failed the PreEmployment drug test must be denied employment as a crewmember; therefore, this 

study could not measure employment outcomes based on the Pre-Employment drug test. 

Moreover, employed crewmembers failing a Random, Reasonable Cause, Periodic, or 

Post-Accident drug test must also be removed from duties which directly affect the safe 

operation of the vessel as soon as practicable, so conducting a study of crewmembers like 
32

Normand et al. (1990) and Zwerling et al. (1990) was not possible for commercial vessel 

crewmembers. 

Fortner, Martin, Esen, and Shelton, (2011) surveyed 1,058 human resource

professionals whose companies had drug testing programs. The participants responded 

from a sample of 6,000 randomly selected from the Society of Human Resource 

Management’s 600,000 members. The human resource professionals answered multiple 

choice questions the Drug and Alcohol Testing Industry Association developed to obtain 

their current opinions about drug testing. They reported a decrease in workers’ 

compensation incidence rates from 14% to 6% after implementing drug testing programs, 

a decrease of 57%. Fortner et al. (2011) also found workers’ compensation premiums 

were lower for companies having mandatory drug testing because it is known drug 

testing will decrease accidents and costs associated with claims. Most relevant to this 

study, Fortner et al. (2011) found Random testing to be the greatest on the job drug abuse 

deterrent because employees do not know when they will be asked to provide a specimen. 

The instant study showed similar results; that is, crewmembers not knowing when the 

Random test will occur will be a great deterrent to drug use. 

The Fortner et al. (2011) results are consistent with Levine and Rennie (2004). 

Levine and Rennie (2004) found that to truly focus on drug detection, Random drug 

testing is better than Pre-Employment drug testing. Pre-Employment drug testing 

encourages employees to simply pass a one-time drug test which will only detect “the 

uninformed, forgetful, or most severely addicted individuals” (Levine and Rennie, 2004, 

p 323). The Fortner study does not indicate whether the human resource respondents also 

relied upon drug testing results to support their answers. This study did not use 
33

questionnaires but instead used drug and alcohol testing results submitted to the Coast 

Guard by marine employers as required by regulation. This eliminated subjective 

responses from crewmembers and their employers and allowed inferences and 

conclusions to come from the data, not the opinions of crewmembers or their employers. 

G. DRUG TESTING RESULTS 

The federal government’s primary contractor for safety-sensitive drug testing is

Quest Diagnostics. Quest’s Drug Testing Index Archives provide an abundance of drug 

testing results going back to 1988, and, for federally-mandated, safety-sensitive drug 

testing results, back to 2007. Since 1988, the annual positivity rates for the combined 

U.S. Workforce have gradually dropped from a high of 13.6% in 1988 to a low of 3.5% 

in 2011. The 2003-2011 rates are shown below: 

Table 1 

Quest Drug Testing Index: Combined U.S. workforce 2003-2011

Year Rate

2003 4.5%

2004 4.5%

2005 4.1%

2006 3.8%

2007 3.8%

2008 3.6%

2009 3.6%

2010 3.5%

2011 3.5%
34

In 2007, Quest started collecting positivity rates for federally-mandated safetysensitive workers. Those rates, compared to others, are shown below: 

Table 2

Quest Drug Testing Index: Federally-mandated safety-sensitive workers 

 Year Rate

2007 1.8%

2008 1.6%

2009 1.5%

2010 1.5%

2011 1.7%

Table 3

Quest Drug Testing Index: General U.S. workforce

 Year Rate

2007 5.7%

2008 5.3%

2009 5.4%

2010 5.3%

2011 5.2%

Table 4 

Quest Drug Testing Index: Federally-mandated safety-sensitive workers

 Year Rate

2007 1.6%

2008 1.4%

2009 1.4%

2010 1.4%

2011 1.5%
35

Table 5

Quest Drug Testing Index: U.S. general workforce

 Year Rate

2007 5.8%

2008 5.6%

2009 5.3%

2010 5.3%

011 5.3%

The Quest data shows a general downward trend in positivity rates. This study’s 

findings are consistent with Quest’s results but go further and compare the trends to show 

the extent to which chemical testing has discouraged drug and alcohol use by commercial 

vessel personnel, reduced the potential for marine casualties related to drug and alcohol 

use, and enhanced the safety of the maritime transportation industry.
36

III. METHODOLOGY

A. OVERVIEW

The methodology used in this study was a secondary data analysis of archived, 

Management Information System (MIS) chemical testing reports and archived, Serious 

Marine Incident (SMI) reports including chemical testing supplements, from 2003 

through 2011. SMI reports and supplements are contained in the Marine Information 

Safety and Law Enforcement (MISLE) system. In 2003, the Coast Guard implemented 

the MISLE system. Among other things, MISLE has made vessel casualty and 

supplemental Post-Accident drug and alcohol testing information more readily available 

and retrievable than previous systems. Readily available and retrievable data is the 

reason this study focuses on the 2003-2011 timeframe. That timeframe is a sufficiently 

long and recent enough period from which to draw conclusions about the Coast Guard’s 

chemical testing program. 

B. DATA COLLECTION MEASURES/PROCEDURES 

A data archive of drug and alcohol test results marine employers are required to 

submit to the Coast Guard was analyzed for this study. This author obtained these data 

archives through requests to the U.S. Coast Guard at efoia@uscg.mil under the Freedom 

of Information Act (FOIA), 5 U.S.C. § 552 (2006); 6 C.F.R. Part 5 (2012).14 The requests 

described this academic study and asked for Marine Information System PreEmployment, Random, Reasonable Cause, and Post-Accident drug testing results from 

2003-2011 that marine employers send to the Coast Guard on a yearly basis. 

 14 See http://www.dhs.gov/xfoia/Copy_of_editorial_0318.shtm.
37

The FOIA request also asked for the yearly 2003-2011 listing of serious marine 

incident reports for commercial fishing vessels and small passenger vessels together with 

Post-Accident drug or alcohol test results. After the initial request, this author was able 

to maintain contact with the appropriate official most knowledgeable of the data available 

and was therefore able to further refine the requests. The listed reports contain the 

number of drug or alcohol tests initiated and the results of those tests. For drug test 

results, it asked only for the number of verified positives for one or more drugs. For 

alcohol tests, it asked only for the number of tests and whether the tests were positive. 

The SMI data were made available in EXCEL® Spreadsheet form and contain no names 

or other personal identifying information. 

The MIS drug testing results were provided in Microsoft Word form and entered 

into EXCEL® spreadsheets. All types of drug tests and corresponding results are 

displayed on a form similar to the form marine employers submit to the Coast Guard on a 

yearly basis. The employers’ yearly reports are compiled and maintained at Coast Guard 

Headquarters. This study did not require names or other personal identifying information 

as part of the data requested. The author asked for and was granted a FOIA fees waiver 

in accordance with 6 C.F.R. § 5.11(d) (4) and (5) (2012) because this is an academic 

study. 

C. DATABASES

The MIS database consists of the following chemical test results from all 

commercial vessel crewmembers subject to chemical testing for the following types of 

drug tests: Pre-Employment, Random, Post-Accident, Reasonable Cause, Return-to-Duty, 

and Follow-up. For each type of chemical test, marine employers list the results on the 
38

U.S. Department of Transportation Drug and Alcohol Testing Management Information 

System (MIS) Data Collection Form in thirteen (13) numbered columns as follows: 1) 

total number of test results; 2) verified negative; 3) verified positive results for one or 

more drugs; 4) positive for marijuana; 5) positive for cocaine; 6) positive for PCP; 7) 

positive for opiates; 8) positive for amphetamines; 9) adulterated; 10) substituted; 11) shy 

bladder with no medical explanation; 12) other refusals to submit to testing; and, 13) 

cancelled results. The totals in columns 1, 2, 3, 9, 10, 11, and 12 comprise the total 

number of test results for each type of test. Cancelled results are not included in the total 

number of test results. Positive results for the presence of specific drugs such as 

marijuana, cocaine, etc., are subsumed in column 3, titled “verified positive results for 

one or more drugs.” Crewmembers’ names or other identifying information are not 

included in the MIS data collection forms. 

The SMI data base in the MISLE system consists of all vessel casualty reports 

meeting the requirements of Serious Marine Incident as described earlier in this proposal 

under the headings “Required Testing” as well as “Records and Reports.” Marine 

employers submit those reports to the Coast Guard on form CG-2692, “Report of Marine 

Accident, Injury or Death” together with a supplemental form entitled “Required 

Chemical Drug and Alcohol Testing Following a Serious Marine Incident,” form CG2692B, as described in 46 C.F.R. §§ 4.05-10, 4.06-60, and 16.240 (2012). 

The numerical relationship of serious marine incidents to all marine casualties is 

displayed in Table 6 on the following page.
39

Table 6 

Serious marine incidents compared to all marine casualties 

CG Marine Casualty Investigations, 2003 – 2011

Calendar 

Year

Not a Serious Marine 

Incident

Serious Marine 

Incident

All Marine Casualty 

Investigations

2003 3,471 594 4,065

2004 3,050 827 3,877

2005 3,026 868 3,894

2006 3,635 961 4,596

2007 3,905 791 4,696

2008 4,067 702 4,769

2009 3,816 662 4,478

2010 4,557 717 5,274

2011 5,136 788 5,924

34,663 6,910 41,573

D. POPULATION AND SAMPLE

There are two populations of crewmembers. One population consists of 

crewmembers subject to chemical testing and the other population consists of 

crewmembers not subject to chemical testing except for Post-Accident drug and alcohol 

tests. Both populations are subject to Post-Accident chemical testing. This study 

compares the Post-Accident chemical testing positivity results for drugs and alcohol 

between the two populations. It also compares the number of Post-Accident, positive 

drug and alcohol tests per serious marine incident in which drug and alcohol tests are 

ordered between both populations. Finally, this study compares the Random and PostAccident positivity rates of all crewmembers subject to chemical testing to show that the 

Random drug test is a good predictor of Post-Accident positivity rates. 
40

Samples from the population subject to chemical testing consist of yearly 2003-

2011 Post-Accident drug and alcohol test results from the SMI database as well as the 

number of serious marine incidents involving one vessel category. Samples from the 

population subject to chemical testing also consist of yearly 2003-2011 Pre-Employment, 

Random, and Post-Accident chemical drug test results from the MIS database. In 

addition to all crewmembers subject to chemical testing from the MIS database, serious 

marine incidents and Post-Accident positivity rates from crewmembers of U.S. 

Documented vessels of 100 gross tons or less certificated for carrying six or more 

passengers for hire were examined.

Samples from the population not subject to comprehensive chemical testing (PreEmployment, Random, etc.) consist of drug and alcohol tests and the number of serious 

marine accidents in the SMI database from crewmembers of U.S. Documented 

commercial fishing vessels. 

The 100 tons or less vessels are more fully described in Subchapters T and K of 

Title 46 Code of Federal Regulations (C.F.R.) and are hereinafter referred to as small 

passenger vessels or SPVs. Small passenger vessel crewmembers in safety sensitive 

positions are subject to chemical testing as well as Coast Guard credentialing or licensing 

requirements. SPVs are also subject to Coast Guard inspection and are the most 

regulated of all U.S. Documented vessels. They are required to be manned with a 

minimum number of credentialed crewmembers in certain positions that are subject to 

watch standing limitations. The vessel’s Certificate of Inspection shows it has met the 

minimum Coast Guard safety standards for fire-extinguishing systems, manning, vessel 

de-watering capabilities, life saving, and navigation equipment. The Certificate of 
41

Inspection also prescribes the maximum number of passengers the vessel may carry. It is 

displayed in an area accessible to passengers. 

U.S. Documented commercial fishing vessels (hereinafter referred to as 

commercial fishing vessels, CFVs, or fishing vessels) are the least regulated of all U.S. 

Documented commercial vessels and are not subject to Coast Guard inspection except for 

some safety features.15 Commercial fishing vessel crewmembers are not subject to Coast 

Guard credentialing or licensing requirements; they have no limits on the time they are on 

duty standing watch; and, they are not required to pass a Pre-Employment chemical test 

or be subject to subsequent Random or Reasonable Cause testing.16 They are, however, 

subject to Post-Accident drug and alcohol testing so they present a perfect contrast to 

small passenger vessel crewmembers for comparison.17 

Table 7 shows the yearly 2003-2009 selected vessel populations of active U.S. 

Documented commercial fishing vessels compared to the population of active U.S. 

Documented small passenger vessels. 

 15 46 C.F.R. § 16.240 (2012); 49 C.F.R. Part 40, Appendix H (2012). Alcohol testing results are submitted 

to the Coast Guard only as part of the Serious Marine Incident Report under 46 C.F.R. § 4.06, not as part of 

the MIS data collection form in accordance with 46 C.F.R. § 16.500(a) (2012).

16 This study refers to Pre-Employment, Random, and Reasonable Cause testing as comprehensive 

chemical testing.

17 Commercial fishing vessels 200 gross tons and above require a licensed master thus subjecting 

crewmembers in safety sensitive positions to comprehensive drug testing in addition to Post-Accident 

testing. The MIS data base may therefore include some Post-Accident drug test results from commercial 

fishing vessels 200 gross tons and above which are also included in the second SMI sample. The number 

of such vessels is relatively small and will not affect the differences in Post-Accident positivity rates 

between the MIS and SMI second samples because the positivity rates are reported to the SMI database as 

well as the MIS database.
42

Table 7 

Populations of commercial fishing vessels compared to small passenger vessels 

Selected Vessel Populations

Calendar 

Year

Commercial Fishing Vessels 

(Documented by USCG)

Small Passenger Vessels 

(T&K)

2003 24,005 6,007

2004 23,528 5,980

2005 22,782 5,709

2006 21,983 5,640

2007 21,584 5,637

2008 21,002 5,784

2009 20,503 5,740

2010 20,060 5,723

2011 19,791 5,680

Selection 

Criteria

[Commercial Fishing Vessel] [In 

Service] [VALID Document]

[Passenger] [Under 100 

GT] [In Service] 

[Inspected]

E. OPERATIONAL DEFINITIONS OF VARIABLES

For Hypotheses 1A and 1B, the independent or predictor variable is the type of 

crewmember measured on a nominal scale comparing two levels: 1) commercial fishing 

vessel crewmembers not subject to chemical testing except for Post-Accident drug and 

alcohol tests; and, 2) small passenger vessel crewmembers subject to chemical testing. 

The dependent variable for Hypothesis 1A is the yearly (SMI) Post-Accident drug 

test positivity rates for one or more drugs. The criterion variable was measured using a 

ratio scale to determine positivity rates. The (SMI) Post-Accident yearly drug test 

positivity rates from commercial fishing vessel crewmembers not otherwise subject to 

chemical testing were determined by dividing the total number of verified positive PostAccident drug test results for one or more drugs each year by the total number of PostAccident drug tests administered to commercial fishing vessel crewmembers for that 
43

year. The SMI Post-Accident yearly drug test positivity rates from small passenger 

vessel crewmembers were determined by dividing the total number of verified positive 

(SMI) Post-Accident drug test results each year by the total number of (SMI) PostAccident drug tests administered to small passenger vessel crewmembers for that year. 

A positive drug test means the test was conducted in accordance with 49 C.F.R. 

pts. 4, 16, and 40 and was reported as “positive” by a Medical Review Officer because 

the test indicated a presence of a dangerous drug or drug metabolite equal to or exceeding 

the cutoff concentrations established in 49 C.F.R. § 40.87 (2012), as shown in Table 8.

Table 8 

Initial and confirmatory drug test cutoff values 

Initial test analyte Initial test cutoff 

concentration

Confirmatory test 

analyte

Confirmatory test 

cutoff concentration

Marijuana 

metabolites

50 ng/mL THCA 15 ng/mL.

Cocaine metabolites 150 ng/mL Benzoylecgonine 100 ng/mL.

Opiate metabolites

Codeine/Morphine 2000 ng/mL Codeine 2000 ng/mL.

 Morphine 2000 ng/mL.

6–Acetylmorphine 10 ng/mL 6–Acetylmorphine 10 ng/mL.

Phencyclidine 25 ng/mL Phencyclidine 25 ng/mL.

Amphetamines

AMP/MAMP 500 ng/mL Amphetamine 250 ng/mL.

 Methamphetamine 250 ng/mL.

MDMA 500 ng/mL MDMA 250 ng/mL.

 MDA 250 ng/mL.

MDEA 250 ng/mL

Source: 65 Fed. Reg. 79,526 (Dec. 19, 2000), as amended by 75 Fed. Reg. 49,862 (Aug. 

16, 2010) codified at 49 C.F.R. § 40.87 (footnotes omitted).
44

Federal Regulations include very specific procedures to prevent the possibility of 

false positive drug tests. Those procedures include: 1) using certified laboratories subject 

to inspection and audit; 2) validating all results by a Medical Review Officer (MRO) for 

each positive determination; and, 3) having pre-defined thresholds for positive test 

determinations. Given these tight controls, the positive drug test results used in this study 

are considered to include few errors.18

The dependent variable for Hypothesis 1B is the same as for Hypotheses 1A 

except it compares the yearly (SMI) Post-Accident alcohol test positivity rates instead of 

drug test positivity rates. A positive test for the presence of alcohol means evidence of 

alcohol to the extent of 0.02 or higher as provided in 49 C.F.R. §§ 40.3 and 40.23.19 

For Hypotheses 1C, the independent or predictor variable is the same as for 

Hypothesis 1A and 1B except this variable is measured using a nominal scale comparing 

two levels: 1) crewmembers on commercial fishing vessels not subject to chemical 

testing except for Post-Accident drug and alcohol tests; and, 2) crewmembers on ALL 

vessels subject to chemical testing. 

The dependent or criterion variable for Hypothesis 1C is the yearly Post-Accident 

drug test rates for one or more drugs. This study measured the criterion variable using a 

ratio scale to determine positivity rates. The (SMI) Post-Accident yearly drug test 

 18 Prior to October 1, 2010, the cocaine metabolite initial test cutoff concentration was 300 ng/ml vice 150 

ng/ml. Also, the amphetamine initial test cutoff was 1000 ng/ml vice 500 ng/ml and the confirmatory test 

cutoff was 500 ng/ml vice 250 ng/ml. For methamphetamine, the old confirmation test cutoff was 500 

ng/ml vice 250 ng/ml. These lower cutoffs will likely produce an increase in the number of positive 

cocaine and amphetamine drug tests which will result in an “uptick” in positivity rates starting in 2011. 

19 The regulations at 49 C.F.R. § 40.23(c) (2012) require the employer that receives an alcohol test result of 

0.04 or higher to remove immediately the employee involved in the accident from performing safetysensitive functions. If the employer receives an alcohol test result of 0.02 – 0.39, the employer must 

temporarily remove the employee involved from performing safety sensitive functions. 
45

positivity rates from commercial fishing vessel crewmembers not otherwise subject to 

chemical testing were determined by dividing the total number of verified positive PostAccident drug test results for one or more drugs each year by the total number of PostAccident drug tests administered to commercial fishing vessel crewmembers for that 

year. The MIS Post-Accident yearly drug test positivity rates from all vessels with

crewmembers subject to chemical testing were determined by dividing the total number 

of verified positive Post-Accident drug test results each year by the total number of PostAccident drug tests administered. 

For Hypotheses 2A and 2B, the independent or predictor variable was the same as 

for Hypotheses 1A and 1B; that is, the type of crewmember. This variable is measured 

using a nominal scale comparing two levels: 1) crewmembers on commercial fishing 

vessels not subject to chemical testing except for Post-Accident drug and alcohol tests; 

and, 2) crewmembers on small passenger vessels subject to chemical testing. 

The dependent or criterion variable for Hypothesis 2A is yearly (SMI) PostAccident positive drug tests for one or more drugs per serous marine incident in which 

drug tests were reported. The criterion variable was measured using a ratio scale to 

determine positive tests per serious marine incident. The (SMI) Post-Accident yearly 

positive drug tests per serious marine incident from commercial fishing vessel 

crewmembers were determined by dividing the yearly number of positive drug tests by 

the yearly number of commercial fishing vessel serious marine incidents in which drug 

tests were reported. 

The dependent or criterion variable for Hypothesis 2B is the yearly (SMI) PostAccident positive alcohol tests per serous marine incident in which alcohol tests were 
46

reported. This study measured the criterion variable using a ratio scale to determine 

positive tests per serious marine incident. The (SMI) Post-Accident yearly positive 

alcohol tests per serious marine incident from commercial fishing vessel crewmembers 

were determined by dividing the yearly number of positive alcohol tests by the yearly 

number of commercial fishing vessel serious marine incidents in which alcohol tests were 

reported. 

For Hypothesis 3, the Predictor Variable is the type of drug test. This variable 

was measured using a nominal scale comparing two levels: 1) Random drug tests of all 

crewmembers subject to chemical testing; and 2) Post-Accident drug tests of all 

crewmembers subject to chemical testing. 

The dependent or criterion variable is the Random and Post-Accident yearly 

positivity rates for one or more drugs using a ratio scale to determine positivity rates. 

The (MIS) Random drug test positivity rates from all vessels with crewmembers subject 

to chemical testing were determined by taking the yearly number of verified positives for 

one or more drugs plus the number of Random drug test refusals which includes 

adulterated, substituted, “shy bladder” with no medical explanation, and other refusals to 

submit to drug testing, and dividing the sum by the total number of Random drug test 

results reported for that year. The Coast Guard used this method to determine Random

positivity rates. The (MIS) Post-Accident drug test positivity rates from all vessels with 

crewmembers subject to chemical testing were determined by taking the yearly number 

of verified positives for one or more drugs and dividing it by the total number of PostAccident tests reported for that year. 
47

IV. ANALYSIS 

Hypotheses 1A and 1B addressed comparisons between yearly and total 2003-

2011 Post-Accident drug and alcohol positivity rates of commercial fishing vessel 

crewmembers and small passenger vessel crewmembers. Hypothesis 1C addressed 

comparisons between yearly and total 2003-2011 Post-Accident drug test positivity rates

of commercial fishing vessel crewmembers and all crewmembers subject to chemical 

testing from all vessels. Hypotheses 2A and 2B addressed comparisons between yearly 

and total 2003-2011 ratios of positive Post-Accident drug and alcohol tests per serious 

marine incident in which drug and alcohol tests were reported of commercial fishing 

vessel crewmembers and small passenger vessel crewmembers. For Hypothesis 3, this 

author examined the relationship between Random and Post-Accident drug test results 

from crewmembers of all vessels to determine how strongly they are correlated and if

Random positivity rates are a good predictor of Post-Accident positivity rates. 

In comparing positivity rates and ratios of positive tests per serious marine 

incident in Hypotheses 1A, 1B, 1C, 2A, and 2B, this author employed tables and 

histograms. To determine if the differences in positivity rates and differences in ratios of 

positive tests per serious marine incident were statistically significant, this author used 

the two proportion z-test for those hypotheses. This author applied that test to compare 

the yearly and total differences in positivity rates and positive tests per serious marine 

incident between two relevant populations, one with crewmembers subject to chemical 
48

testing and one not subject to chemical testing except for Post-Accident drug and alcohol 

testing.20 

Utilizing the two proportion z-test was based on the following assumptions: 1) the 

samples are categorical and independent; 2) crewmembers selected for drug and alcohol 

tests are selected as the result of a serious marine incident which is a random occurrence; 

3) the test results are either positive or negative; 4) the predictor variable has two levels 

measured on a nominal scale – crewmembers subject to chemical testing and 

crewmembers not subject to chemical testing; 5) the number of tests in the samples is 

large - thirty and above; and, 6) ratio scale is used to determine positivity rates and 

positive tests per serious marine incident. The two proportion z test can also be used to 

examine each year individually. 

In comparing Random and Post-Accident positivity rates in Hypothesis 3, I used 

the correlation coefficient and linear regression analysis to determine if there is a 

relationship between Random and Post-Accident positivity rates from all vessels with 

crewmembers subject to chemical testing. For all hypotheses, except Hypothesis 3, the 

null hypothesis would be zero; that is, there is no difference between the population 

proportions. For Hypotheses 1A and 1B, the alternative Hypotheses is commercial 

fishing vessel crewmember positivity population proportion is greater than the small 

passenger vessel crewmember proportion. For Hypotheses 1C, the alternative 

Hypothesis that the commercial fishing vessel crewmember population proportion is 

greater than the crewmember population proportion of all vessels subject to chemical 

 20 “Subject to chemical testing” means subject to the prescriptions in 46 C.F.R. pt. 16; that is, subject to 

Pre-employment, Random, and Periodic as well as Post-Accident. 
49

testing. For Hypotheses 2A and 2B, the alternative Hypotheses is commercial fishing 

vessel population proportions are greater than the small passenger vessel proportions. 

For Hypothesis 3, the null hypothesis is that there is no correlation. The alternative 

Hypothesis is there is a strong correlation between the two population proportions. For 

statistical tests in Hypotheses 1A, 1B, 1C, 2A, and 2B, the alpha level was set a priori at 

.05. 

Rumsey (2011, pp. 240-42) explains the two-proportion z-test in easy to 

understand terms as does Larson and Farber (2009, pp. 407, 425) and Moore, McCabe, 

and Craig (2009, pp. 512-16). Simple explanations are also found under Statistical 

Hypothesis Testing, Common Test Statistics at wikipedia.org and at stattrek.com under 

Hypothesis Test: Difference Between Proportions. The two proportion z test formula is 

as follows:

This formula compares differences in positivity rates (numerator) to the overall, 

or pooled, variation of the test results (denominator). The values p1 and p2 represent 

positivity rates in Hypotheses 1A, 1B, and 1C and ratios of positive tests per serious 

marine incident in Hypotheses 2A and 2B. For Hypotheses 1A, 1B, and 1C, those values 

are obtained by dividing the yearly, 2003-2011 Post-Accident positive drug or alcohol 

tests by the yearly number of tests administered for each variable. For Hypotheses 2A 

and 2B, those values are obtained by dividing the yearly 2003-2011 Post-Accident 

positive drug or alcohol tests by the yearly 2003-2011 number of serious marine 

incidents in which drug or alcohol tests were conducted for each variable. 
50

For Hypotheses 1A, 1B, and 1C, the letter p represents the sum of Post-Accident 

positive drug or alcohol tests from each variable each year divided by the sum of PostAccident drug or alcohol tests administered from each variable. For Hypotheses 2A and 

2B, the letter p represents the sum of Post-Accident positive drug or alcohol tests from 

each variable each year divided by the sum of serious marine incidents each year from 

each variable in which drug or alcohol tests were reported. 

For Hypotheses 1A, 1B, and 1C, the letter n represents the number of PostAccident tests administered for each variable each year. In the case of determining the z 

test statistic or z score for all cumulative years, it is the total number of positive tests for 

all years divided by the total number of tests administered for Hypotheses 1A, 1B, and 

1C. For Hypotheses 2A and 2B, it is the total number of positive tests divided by the 

total number of serious marine incidents. As shown in the tables, this study applies the 

two proportion z-test formula to the values each year as well as to the totals in order to 

arrive at the test statistic or z score for that year. 

Hypothesis 3 examines the relationship between Post-Accident drug test positivity 

rates and Random drug test positivity rates from all vessels with crewmembers subject to 

chemical testing. This author tested Hypothesis 3 using linear regression and the 

correlation coefficient.
51

V. HYPOTHESIS 1A

In response to the first research question “[t]o what extent, if any, has chemical 

testing discouraged drug and alcohol use by commercial vessel personnel,” recall that

Hypothesis 1A states yearly 2003-2011 Post-Accident drug test positivity rates from 

small passenger vessel crewmembers subject to chemical testing are significantly lower 

than yearly 2003-2011 Post-Accident drug test positivity rates from commercial fishing 

vessel crewmembers not otherwise subject to chemical testing. The Null Hypothesis is 

there is no difference in the Post-Accident positivity rates between the two groups. 

The yearly 2003-2011 Post-Accident drug tests, verified positives, and resulting 

positivity rates for commercial fishing vessels and small passenger vessels are displayed 

in Table 9 below. 

Table 9 

CFV and SPV Post-Accident drug tests and results 

Commercial Fishing Vessels Small Passenger Vessels

 (CFV) (SPV)

 

Year Drug Tests Positives Rate Drug Tests Positives Rate

2003 68 22 0.3235 64 3 0.0469

2004 82 19 0.2317 142 6 0.0426

2005 110 14 0.1274 107 3 0.0280

2006 160 28 0.1750 123 9 0.0732

2007 136 23 0.1691 122 3 0.0246

2008 100 12 0.1200 98 8 0.0818

2009 97 26 0.2680 84 1 0.0119

2010 73 14 0.1918 129 2 0.0155

2011 88 19 0.2159 152 4 0.0263

Mean 0.2025 0.0389

STDEV 0.0656 0.0246

 

 
52

Table 9 shows a decrease in positivity rates with occasional upward positivity 

spikes in both categories. A variety of factors could change the year after year positivity 

rates. For example, the 2011 increase may be attributed in part to lower initial and 

confirmatory test cutoff values; however, it is too early to see if the lower cutoff values 

show a trend with only one year’s data. It will be necessary to collect a few more years 

of data to confirm a trend. There may be many other reasons for variations in the 

positivity rates within each category. The smaller the number of tests and corresponding 

results, the greater the likelihood of dramatic percentage changes in positivity for any 

given year. A small number of tests also may be attributed to crewmembers being 

unavailable for testing because they and their fishing vessels were lost at sea. The

differences in positivity rates from one year to the next may vary greatly in both vessel 

categories but the 2003-2011 positivity rates of commercial fishing vessels are always 

higher than the positivity rates of small passenger vessels as shown in Figure 1 below. 

Figure 1 

Differences between CFV and SPV Post-Accident drug test positivity rates
53

As shown in Table 10, Post-Accident drug test positivity rates of SPVs with 

crewmembers subject to chemical testing are significantly lower than drug test positivity 

rates of CFVs with crewmembers not otherwise subject to chemical testing. Table 10 

shows Post-Accident drug test positivity rates of SPV crewmembers at least 32% lower 

(2008) and as much as 96% lower (2009) than Post-Accident drug test positivity rates of 

CFV crewmembers. Small passenger vessel crewmembers had an average of 77% fewer 

Post-Accident positive drug tests than commercial fishing vessel crewmembers. 

Table 10 

Yearly percentage differences between CFV and SPV drug test positivity rates

The tables and the histogram show large differences in Post-Accident drug test 

positivity rates between CFV crewmembers and SPV crewmembers. To determine if 

these differences are statistically significant at the 0.05 level and therefore not due to 

chance, the study used the two proportion z-test. 

Applying the two proportion z-test formula discussed in Chapter IV, Table 11 

shows the z-test scores and corresponding statistical values for yearly and total, overall 

Post-Accident positivity rates between CFV and SPV crewmembers. In seven out of nine 

Year

CFV positivity 

rates in %

SPV positivity 

rates in %

+ or – diff in %

2003 32.35 4.69 -86

2004 23.17 4.26 -82

2005 12.74 2.80 -78

2006 17.50 7.32 -58

2007 16.91 2.46 -86

2008 12.00 8.18 -32

2009 26.80 1.19 -96

2010 19.18 1.55 -92

2011 21.59 2.63 -88
54

years, the differences in positivity rates are statistically significant at the 0.01 level; that 

is, the probability that the differences in positivity rates are due to chance is less than one 

percent. In 2005, p = 0.012, thus statistically significant at the 0.05 level. In 2008, the 

differences are not statistically significant at p = 0.19. When comparing the total, overall 

results, the z-test shows the differences in Post-Accident positivity rates between CFV 

crewmembers and SPV crewmembers is still less than 0.01 and thus statistically 

significant. 

Table 11 

CFV and SPV Post-Accident drug test z scores with p values 

 Commercial Fishing Vessels Small Passenger Vessels 

 (CFV) (SPV) 

 

Year Drug Tests Positives Rate Drug Tests Positives Rate z score p value

2003 68 22 0.3235 64 3 0.0469 4.054 *p = 0.01

2004 82 19 0.2317 142 6 0.0426 4.338 *p = 0.01

2005 100 14 0.1274 107 3 0.0280 2.270 *p = .012

2006 160 28 0.1750 123 9 0.0732 2.519 *p = 0.01

2007 136 23 0.1691 122 3 0.0246 3.850 *p = 0.01

2008 100 12 0.1200 98 8 0.0818 0.896 p = 0.19

2009 97 26 0.2680 84 1 0.0119 4.824 *p = 0.01

2010 73 14 0.1918 129 2 0.0155 4.457 *p = 0.01

2011 88 19 0.2159 152 4 0.0263 4.808 *p = 0.01

Total 917 177 0.1937 1021 39 0.0382 10.841 *p = 0.01

*Indicates statistically significant.

Given the results of the other eight years, the 2008 Post-Accident z-score might be 

considered an “outlier” or anomaly. There are some known “special causes” that may 

explain it. The CFV vessel drug test positivity rate was the lowest for the nine year 

period. It is possible that some commercial fishing vessel crewmember tests were not 

conducted due to the following: 1) serious marine incidents in remote locations, 2) the 

severity of the accidents and injuries, 3) the inability to rescue in a timely manner, or 4) 
55

the crewmembers and their vessels were lost at sea. Conversely, the 2008 SPV

crewmember Post-Accident drug test positivity rate is the highest of the nine-year period. 

This result may be due to a drop in the number of tests performed in 2008. Also, the 

number of positive tests in any year is small enough that one casualty with multiple 

vessels or multiple involved crewmembers can skew the results. These data for this 

hypothesis are person-specific, not incident-specific. To determine if a special cause 

contributed to this statistical anomaly it would be necessary to examine the Coast Guard 

casualty data in more detail. Such a review is possible, but beyond the scope of this 

study. 

The two proportion z-test showed the total, overall differences in Post-Accident 

positivity rates between SPV crewmembers and CFV crewmembers to be statistically 

significant.
56

VI. HYPOTHESIS 1B

Also in response to the first research question “[t]o what extent, if any, has 

chemical testing discouraged drug and alcohol use by commercial vessel personnel” 

Hypothesis 1B states yearly 2003-2011 Post-Accident alcohol test positivity rates from 

small passenger vessel crewmembers subject to chemical testing are significantly lower 

than yearly 2003-2011 Post-Accident alcohol test positivity rates from commercial

fishing vessel crewmembers not otherwise subject to chemical testing. The Null 

Hypothesis is there is no difference in Post-Accident alcohol test positivity rates between 

the two groups.

The yearly 2003-2011 Post-Accident alcohol (ETOH) tests, positives, and 

resulting positivity rates for CFVs and SPVs are displayed in Table 12. “ETOH” is the 

chemical abbreviation of ethyl alcohol and is used in the tables and figures to refer to 

chemical tests specifically for alcohol. As with drug test positivity rates in Hypothesis 

1A, ETOH positivity rates for both CFV crewmembers and SPV crewmembers gradually 

decrease year after year, with occasional upward spikes. 

There is a gradual decrease with occasional upward positivity spikes in both 

categories. There may be many reasons for the differences in alcohol positivity rates 

within each separate category, including the availability of crewmembers to test for drugs 

and alcohol and the requirement that the alcohol test be administered within two hours of 

the serious marine incident. As is often the case with CFVs, crewmembers may not be 

available to test because they and their vessels may be lost at sea.
57

Table 12

CFV and SPV Post-Accident alcohol tests and results

 Commercial Fishing Vessels Small Passenger Vessels

 (CFV) (SPV)

 

Year ETOH Tests Positives Rate ETOH Tests Positives Rate

 a b c d e f

2003 16 3 0.1875 16 1 0.0626

2004 26 5 0.1923 88 3 0.0341

2005 29 2 0.0689 69 1 0.0145

2006 67 5 0.0746 83 0 0

2007 61 3 0.0492 118 5 0.0424

2008 51 3 0.0588 76 0 0

2009 45 3 0.0666 72 1 0.0139

2010 43 2 0.0465 123 0 0

2011 91 1 0.0110 136 1 0.0074

Mean 0.0839 0.0194

STDEV 0.0629 0.0222

Another contributing factor is the number of positives in any year is quite small so 

one serious marine incident can markedly affect the positivity rate for that year. Despite 

spikes in positivity, Post-Accident alcohol test positivity rates of SPVs with 

crewmembers subject to chemical testing are much lower than CFVs with crewmembers 

not otherwise subject to chemical as shown in the Figure 2 histogram below.
58

Figure 2 

Differences between CFV and SPV alcohol test positivity rates

Table 13 shows the year after year Post-Accident alcohol test positivity rates of 

SPV crewmembers to be at least 14% lower (2007), and as much as 100% lower (2006, 

2008, and 2010) than Post-Accident alcohol positivity rates of CFV crewmembers. SPV 

crewmembers averaged 73% fewer Post-Accident positive alcohol tests than CFV 

crewmembers. 

Table 13 

Alcohol positivity rates of CFV crewmembers versus SPV crewmembers

Year CFV Crewmember 

ETOH positivity 

rates in percentages

SPV Crewmember 

ETOH positivity 

rates in percentages

% differences of 

SPV vs. CFV 

Crewmembers

2003 0.1875 0.0626 -67%

2004 0.1923 0.0341 -82%

2005 0.0689 0.0145 -79%

2006 0.0746 0 -100%

2007 0.0492 0.0424 -14%

2008 0.0588 0 -100%

2009 0.0666 0.0139 -79%

2010 0.0465 0 -100%
59

2011 0.0110 0.0074 -33%

The tables and histogram show large differences in Post-Accident alcohol test 

positivity rates between commercial fishing vessel crewmembers and small passenger 

vessel crewmembers. To determine if these differences are statistically significant at the 

0.05 level and therefore not due to chance, this study uses the two proportion z-test as 

discussed in Chapter IV. 

Table 14 shows the z-test scores and corresponding statistical values for yearly 

and total, overall Post-Accident alcohol test positivity rates between CFV and SPV 

crewmembers. In four out of nine years, the differences in positivity rates are statistically 

significant. In 2003, 2005, 2007, 2009, and 2011 the probabilities were greater than 0.05 

and thus not statistically significant. When comparing the total, overall Post-Accident 

alcohol positivity rates, the z-test shows the differences are statistically significant. 

Table 14 

CFV and SPV Post-Accident alcohol tests, z scores with p values 

 Commercial Fishing Vessels Small Passenger Vessels 

 (CFV) (SPV) 

Year ETOH Tests Positives Rate ETOH Tests Positives Rate z score p value 

2003 16 3 0.1875 16 1 0.0626 1.069 0.1446

2004 26 5 0.1875 88 3 0.0341 2.774 *0.0028

2005 29 5 0.0689 69 1 0.0145 1.428 0.4129

2006 67 5 0.0746 83 0 0 2.531 *0.0057

2007 61 3 0.0492 118 5 0.0424 0.2089 0.4207

2008 51 3 0.0588 76 0 0 2.139 *0.0069

2009 45 3 0.0666 72 1 0.0139 1.528 0.0643

2010 43 2 0.0465 123 0 0 2.406 *0.0082

2011 91 1 0.0110 136 1 0.0074 0.287 0.3897

Total 429 27 0.0629 781 12 0.0154 4.482 *< 0.01

*Indicates statistically significant.
60

There is a gradual decrease with occasional upward positivity spikes in both 

categories which may be attributed to the availability of crewmembers to test for drugs 

and alcohol as noted in the discussion under Hypothesis 1A. The SMI’s remoteness is 

more acute in alcohol testing because the test must be given within two hours of the 

accident. 
61

VII. HYPOTHESIS 1C

In final response to the first research question “[t]o what extent, if any, has 

chemical testing discouraged drug and alcohol use by commercial vessel personnel” 

Hypothesis 1C states yearly 2003-2011 Post-Accident drug test positivity rates from all 

crewmembers subject to chemical testing from all vessels are significantly lower than 

yearly 2003-2011 Post-Accident drug test positivity rates from commercial fishing vessel 

crewmembers not otherwise subject to chemical testing. The Null Hypothesis is there is 

no difference in drug test positivity rates between the two groups.

The yearly 2003-2011 numbers of Post-Accident drug tests, verified positives, 

and resulting positivity rates for CFV crewmembers and Post-Accident drug tests, 

verified positives, and positivity rates for ALL vessels with crewmembers subject to 

chemical testing are displayed in Table 15. As with Hypotheses 1A and 1B, the PostAccident drug test positivity rates of all crewmembers subject to chemical testing are 

much lower than the drug test positivity rates of CFV crewmembers not otherwise subject 

to chemical testing. As expected, the Post-Accident drug test positivity rates of all 

crewmembers from all vessels gradually decrease year after year at about the same rate as 

commercial fishing vessel Post-Accident drug test rates. 
62

Table 15 

Post-Accident drug test positivity rates, commercial fishing vessels versus all vessels

 

Commercial Fishing Vessels ALL Vessels

 (CFV) (ALL)

 

Year Drug Tests Positives Rate Drug Tests Positives Rate

2003 68 22 0.3225 5,295 165 0.0312

2004 82 19 0.2317 4,579 86 0.0188

2005 110 14 0.1274 6,263 90 0.0144

2006 160 28 0.1750 6,300 87 0.0138

2007 136 23 0.1691 7,211 115 0.0159

2008 100 12 0.1200 7,259 95 0.0131

2009 97 26 0.2680 6,497 60 0.0092

2010 73 14 0.1918 6,857 57 0.0083

2011 88 19 0.2159 6,941 67 0.0097

Mean 0.2024 0.0149

STDEV 0.0616 0.0065

As with Hypotheses 1A and 1B, there are gradual decreases with occasional 

spikes in positivity from 2003-2011. The reasons for the spikes were discussed in those 

hypotheses. Despite spikes in positivity, Post-Accident drug test positivity rates of all 

vessels with crewmembers subject to comprehensive chemical testing are always lower 

than CFVs with crewmembers not subject to comprehensive chemical drug testing except 

for Post-Accident drugs and alcohol as shown in the Figure 3 histogram below.
63

Figure 3 

Differences between CFV and ALL drug test positivity rates

The tables and the histogram for Hypothesis 1C show that the differences in PostAccident drug test positivity rates between CFV crewmembers and all crewmembers 

subject to comprehensive chemical testing are much greater than the differences between 

CFV crewmembers and SPV crewmembers. 

As shown in Table 16, Post-Accident positivity rates of crewmembers subject to 

chemical testing from ALL vessels are at least 89% lower (2008) and as much as 97% 

lower (2009) than Post-Accident positivity rates of commercial fishing vessel 

crewmembers. Crewmembers subject to comprehensive chemical testing from ALL 

vessels averaged 92% fewer Post-Accident positive drug tests than crewmembers of 

commercial fishing vessels not subject to comprehensive chemical testing except for 

Post-Accident drug and alcohol tests. 
64

Table 16 

Percentage differences in CFV drug test positivity rates compared to all vessels 

Year CFV positivity rates 

in percentages

ALL positivity rates 

in percentages

+ or – diff in %

2003 0.3225 0.0312 -90%

2004 0.2317 0.0188 -92%

2005 0.1274 0.0144 -89%

2006 0.1750 0.0138 -92%

2007 0.1691 0.0159 -90%

2008 0.1200 0.0131 -89%

2009 0.2680 0.0092 -97%

2010 0.1918 0.0083 -96%

2011 0.2159 0.0097 -96%

Applying the two proportion z-test formula discussed in Chapter IV, Table 17 

shows the z-test scores and corresponding statistical values for yearly and overall PostAccident positivity rates between commercial fishing vessel and small passenger vessel 

crewmembers. In all years, the differences in positivity rates are statistically significant 

at the 0.01 level; that is, the probability that the differences are due to chance is less than 

1%.

Here, the z scores are so high they are “off the chart,” meaning the p value is 

significantly below 0.01; therefore, < 0.01 is placed in the box. While the positivity rates 

in both categories gradually decrease year after year, perhaps due to the general decline 

in drug use as reflected in the Quest Diagnostics statistics and the DOD studies, the

differences are still statistically significant. We know that crewmembers of all vessels, 

except commercial fishing vessels less than 200 tons without a licensed master, are 

subject to chemical testing. Given that the primary difference between the two groups is 
65

that one group is subject to comprehensive chemical testing and the other is not, the 

differences in positivity rates is startling.

Table 17 

CFV Post-Accident positive drug test rates compared to ALL vessels with z scores 

and p values

 Commercial Fishing Vessels ALL Vessels

 (CFV) (ALL) 

 

 Drug Tests Positives Rate Drug Tests Positives Rate z score p value

2003 68 22 0.3225 5,295 165 0.0312 13.0587 *<0.01

2004 82 19 0.2317 4,579 86 0.0188 12.8598 *<0.01

2005 110 14 0.1274 6,263 90 0.0144 09.2650 *<0.01

2006 160 28 0.1750 6,300 87 0.0138 15.2272 *<0.01

2007 136 23 0.1691 7,211 115 0.0159 13.0352 *<0.01

2008 100 12 0.1200 7,259 95 0.0131 08.8706 *<0.01

2009 97 26 0.2680 6,497 60 0.0092 22.3006 *<0.01

2010 73 14 0.1918 6,857 57 0.0083 15.4844 *<0.01

2011 88 19 0.2159 6,941 67 0.0097 17.4897 *<0.01

Total 914 177 0.1936 57,202 822 0.0144 41.3716 *<0.01

*Indicates statistically significant.

 
66

VIII. HYPOTHESIS 2A

In response to the second research question “[t]o what extent, if any, does 

chemical testing reduce the potential for marine casualties related to drug and alcohol 

use” Hypothesis 2A states yearly 2003-2011 ratios of Post-Accident positive drug tests 

per serious marine incident from small passenger vessel crewmembers subject to 

chemical testing are significantly lower than corresponding Post-Accident positive drug 

tests per serious marine incident from commercial fishing vessel crewmembers not 

otherwise subject to chemical testing. The Null Hypothesis is there is no difference in 

Post-Accident positive drug tests per serious marine incident between the two groups. 

The yearly 2003 through 2011 Post-Accident positive drug tests and the yearly 

2003-2011 serious marine incidents in which drug tests are reported are shown for 

commercial fishing vessels and small passenger vessels in Table 19. Counting only 

serious marine incidents in which drug tests are reported eliminates possible variations 

due to differing crew sizes or the number of directly involved crewmembers. In short, it 

is more accurate. CFV positive drug tests per SMI in which Post-Accident drug tests are 

reported are much higher than SPV positive drug tests per SMI in which drug tests are 

reported. 
67

Table 18 

Ratios of CFV and SPV Post-Accident positive drug tests per SMI

 Commercial Fishing Vessels Small Passenger Vessels

 (CFV) (SPV)

 

Year SMIs Positive Ratio SMIs Positive Ratio

 Drug Tests Drug Tests

2003 27 12 0.4444 26 2 0.0769

2004 38 13 0.3421 63 6 0.0952

2005 62 9 0.1451 45 3 0.0666

2006 106 18 0.1698 58 8 0.1379

2007 69 13 0.1884 50 3 0.0600

2008 53 8 0.1509 40 5 0.1250

2009 44 15 0.3409 44 1 0.0227

2010 45 11 0.2444 51 1 0.0196

2011 40 13 0.3250 58 4 0.0689

Mean 0.2612 0.0748

STDEV 0.1061 0.0403

As with Hypotheses 1A and 1B, there are gradual decreases with occasional 

spikes in positivity from 2003-2011. The reasons for the spikes were discussed in those 

hypotheses. Despite spikes in positivity, Post-Accident positive drug tests per serious 

marine incident of all vessels with crewmembers subject to comprehensive chemical 

testing are always lower than positive drug tests per SMI of CFVs with crewmembers not 

subject to comprehensive chemical testing except for Post-Accident drugs and alcohol as 

shown in the Figure 4 histogram below. Because of the relatively small numbers, a few 

more or less positive tests can affect large changes in the ratios. 
68

Figure 4 

Differences between CFV and SPV positive drug tests per SMI

Table 19 

Percentage differences between CFV and SPV positive drug tests per SMI

 

Year

CFV positive drug 

tests per SMI 

(column “c” from 

Table 13)

SPV positive drug 

tests per SMI 

(column “f” from 

Figure 13)

% difference that 

SPV ratios are less 

than CFV ratios.

2003 0.4444 0.0769 -83%

2004 0.3421 0.0952 -72%

2005 0.1451 0.0666 -54%

2006 0.1698 0.1379 -19%

2007 0.1884 0.0600 -68%

2008 0.1509 0.1250 -17%

2009 0.3409 0.0227 -93%

2010 0.2444 0.0196 -93%

2011 0.3250 0.0689 -79%

Table 19 shows the SPV crewmember percentage of Post-Accident positive drug 

tests per serious marine incident in which a drug test is reported to be at least 17% lower 

(2008) and as much as 93% lower (2010) than the CFV Post-Accident positive drug tests 
69

per SMI for any year, 2003-2011. During that time period, the SPV ratios of PostAccident positive drug tests per SMI averaged 64% lower than the CFV Post-Accident 

positive drug test per SMI. 

The tables and the histogram for Hypothesis 2A show the differences in PostAccident positive drug tests per SMI between CFV crewmembers subject to 

comprehensive chemical testing and crewmembers of SPVs not subject to comprehensive 

chemical testing. To determine if these differences are statistically significant at the 0.05 

level and therefore not due to chance, I used the two proportion z-test as described in 

Chapter IV. 

Table 20 shows z-test scores and corresponding p values for yearly and overall 

Post-Accident positive drug tests per serious marine incident between CFV and SPV 

crewmembers. In five out of nine years (2003, 2004, 2009, 2010, and 2011), the 

differences in positivity rates are statistically significant at the 0.05 level. In this case, the 

p values are less than 0.01; that is, the probability that the differences in positivity rates 

are due to chance is less than one percent. In 2007, the differences are statistically 

significant at the 0.05 level with a p value of 0.02. In 2005, 2006, and 2008 the 

differences are not statistically significant but the total, overall results are statistically 

significant. 
70

Table 20 

Ratios of CFV and SPV Post-Accident positive drug tests per SMI with z scores and 

p values

 Commercial Fishing Vessels Small Passenger Vessels

 (CFV) (SPV)

 Positive Positive

 Drug Drug

 SMIs Tests Ratio SMIs Tests Ratio z score p value

2003 27 12 0.4444 26 2 0.0769 3.034 *< 0.01

2004 38 13 0.3421 63 6 0.0952 3.075 *< 0.01

2005 62 9 0.1451 45 3 0.0666 1.270 0.102

2006 106 18 0.1698 58 8 0.1379 0.534 0.2955

2007 69 13 0.1884 50 3 0.0600 2.027 *0.0212

2008 53 8 0.1509 40 5 0.1250 0.357 0.3615

2009 44 15 0.3409 44 1 0.0227 3.869 *< 0.01

2010 45 11 0.2444 51 1 0.0196 3.324 *< 0.01

2011 40 13 0.3250 58 4 0.0689 3.290 *< 0.01

Total 484 112 0.2314 435 33 0.0758 6.458 *< 0.01

*Indicates statistically significant.
71

IX. HYPOTHESIS 2B

In further response to research question number two “[t]o what extent, if any, 

does chemical testing reduce the potential for marine casualties related to drug and 

alcohol use” Hypothesis 2B states the yearly 2003-2011 ratios of Post-Accident positive 

alcohol tests per serious marine incident from small passenger vessel crewmembers 

subject to chemical testing are significantly lower than corresponding Post-Accident 

positive alcohol tests per serious marine incident from commercial fishing vessel 

crewmembers not otherwise subject to chemical testing. The Null Hypothesis is there is 

no difference in positive alcohol tests per serious marine incident between the two 

groups. 

The yearly 2003 through 2011 Post-Accident positive alcohol tests and the yearly 

2003-2011 SMIs in which alcohol tests are reported are shown for CFVs and SPVs in 

Table 21. Counting only serious marine incidents in which alcohol tests are reported

eliminates possible variations due to differing crew sizes or the number of directly 

involved crewmembers. In short, it is more accurate. As the table shows, the ratio of 

CFV positive alcohol tests per SMI is much higher than the ratio of SPV positive alcohol 

tests per SMI. The CFV ratio of positive alcohol tests per SMI gradually decreases as 

does the SPV ratio of positive alcohol tests per SMI but not as dramatically.
72

Table 21 

Ratios of CFV and SPV Post-Accident positive alcohol tests to SMIs 

 Commercial Fishing Vessels Small Passenger Vessel

 (CFV) (SPV)

 

 Year SMIs Positive Ratio SMIs Positive Ratio 

 ETOH Tests ETOH Tests

2003 8 2 0.2500 7 1 0.0143

2004 15 5 0.3333 33 3 0.0909

2005 21 2 0.0952 30 1 0.0333

2006 32 3 0.0937 30 0 0.0000

2007 33 3 0.0909 48 4 0.0833

2008 30 2 0.0625 35 0 0.0000

2009 25 3 0.12 39 1 0.0256

2010 23 1 0.0434 46 0 0.0000

2011 35 1 0.0285 53 1 0.0188

Mean 0.12417 0.0296

STDEV 0.10120 0.0347

Table 21 shows positive alcohol tests per SMI in both categories. There are 

spikes in positivity but the number of tests and results are very small which may account 

for such spikes. In all years, the SPV positive alcohol tests per SMI in which alcohol 

tests were reported were consistently less than CFV positive alcohol tests per SMI in 

which alcohol tests were reported as shown in the Figure 5 histogram.
73

Figure 5 

Differences between CFV and SPV positive alcohol (ETOH) tests per SMI

Table 22 below compares ratios of positive alcohol tests per SMI and the 

percentage differences for each year, 2003-2011. It shows the SPV crewmember 

percentage of Post-Accident positive alcohol tests per SMI in which a Post-Accident test 

is reported to be at least 8% lower (2007) and as much as 100% lower (2006, 2008, and 

2010) than CFV crewmember Post-Accident positive alcohol tests per SMI for any year. 

During that time period, the SPV ratios of Post-Accident positive alcohol tests per SMI 

averaged 73% lower than the CFV Post-Accident positive alcohol tests per SMI. 
74

Table 22 

Percentage differences between CFV and SPV positive alcohol tests per SMI 

 

Year CFV positive ETOH 

tests per SMI 

(column “c” from 

Figure 16)

SPV positive ETOH 

tests per SMI 

(column “f” from 

Figure 16)

% difference that 

SPV ratios are less 

than CFV ratios.

2003 0.2500 0.0143 -94%

2004 0.3333 0.0909 -73%

2005 0.0952 0.0333 -65%

2006 0.0937 0.0000 -100%

2007 0.0909 0.0833 -8%

2008 0.0625 0.0000 -100%

2009 0.1200 0.0256 -79%

2010 0.0434 0.0000 -100%

2011 0.0285 0.0188 -34%

The tables and the histogram for Hypothesis 2B show the differences in PostAccident alcohol positive tests per SMI between CFV crewmembers subject to 

comprehensive chemical testing and SPV crewmembers not subject to comprehensive 

chemical testing. To determine if these differences are statistically significant at the p = 

0.05 level and therefore not due to chance, I used the two proportion z-test. Table 23 

shows the z-test scores and corresponding statistical values for yearly and overall PostAccident positive alcohol tests per SMI between CFV crewmembers and SPV 

crewmembers. Although the differences are not statistically significant in seven out of 

nine years with p values ranging from 0.06 to 0.38, the p value for the 2003-2011 total, 

overall results is 0.0007, and thus statistically significant. 
75

Table 23 

Ratios of CFV and SPV Post-Accident positive alcohol tests per SMI with z scores 

and p values

Commercial Fishing Vessels Small Passenger Vessel

 (CFV) (SPV)

 

Year SMIs positives ratio SMIs positives ratio z scores p values

2003 8 2 0.2500 7 1 0.0143 0.518 0.305

2004 15 5 0.3333 33 3 0.0909 2.089 *0.023

2005 21 2 0.0952 30 1 0.0333 0.925 0.179

2006 32 3 0.0937 30 0 0.0000 1.719 *0.044

2007 33 3 0.0909 48 4 0.0833 0.119 0.117

2008 30 2 0.0625 35 0 0.0000 1.552 0.061

2009 25 3 0.12 39 1 0.0256 1.521 0.066

2010 23 1 0.0434 46 0 0.0000 1.425 0.078

2011 35 1 0.0285 53 1 0.0188 0.299 0.386

Total 222 22 0.0991 321 11 0.0342 3.109 *0.0007

*Indicates statistically significant.

 

As with large variations in alcohol test results in Hypothesis 1B, similar variations 

exist in Hypothesis 2B. Two factors are known to contribute to these variations. The 

first factor is the two hour time period in which alcohol tests must be ordered. This time 

limitation on alcohol testing will leave out many instances in which tests could be 

ordered but for the remoteness of the vessel’s location, especially CFVs that ordinarily 

operate farther offshore than SPVs. The second factor is the relatively small number of 

tests that could cause wide swings in percentages of positive tests per SMI. Even with 

these factors, the ratio of positive alcohol tests per SMI consistently shows crewmembers 

of SPVs test positive for alcohol less than CFV crewmembers and the results are 

statistically significant overall. 
76

X. HYPOTHESIS 3

In response to the third research question “[t]o what extent, if any, does chemical 

testing enhance the safety of the maritime transportation industry” Hypothesis 3 states the 

yearly 2003-2011 Post-Accident drug test positivity rates from all vessels with 

crewmembers subject to chemical testing will correlate positively and strongly with 

decreasingly lower Random drug test positivity rates from 2003-2011 for all vessels with 

crewmembers subject to chemical testing. The Null Hypothesis is that there is no

correlation of Post-Accident positivity with downward Random positivity rates. 

Table 24 shows yearly 2003 through 2011 Pre-Employment, Random, and PostAccident Random drug test positivity rates from ALL vessels with crewmembers subject 

to chemical testing. The Pre-Employment positivity rate is obtained by dividing the total 

number of Verified Positive Test Results by the total number of Pre-Employment drug 

tests. For 2011, the total number of Pre-Employment, Verified Positive Test Results is 

1,723 and the total number of Pre-Employment drug tests is 46,746. Dividing the total 

number of Pre-Employment positive drug tests by the total number of tests yields a PreEmployment positivity rate of .03685. The positivity rates for Post-Accident are obtained 

in the same manner; however, the Coast Guard calculates the Random positivity rate 

differently. 
77

Table 24 

MIS Pre-Employment, Random, and Post-Accident positivity rates

 Pre-Employment Random Post-Accident

 ALL ALL ALL

Year Tests Positives Rate Tests Positives Rate Tests Positives Rate

2003 37,984 1,043 0.02745 45,845 944 0.02059 5,295 165 0.03116

2004 36,737 1,041 0.02833 43,004 657 0.01527 4,579 86 0.01878

2005 51,177 1,391 0.02718 53,661 779 0.01451 6,263 90 0.01437

2006 56,612 2,053 0.03626 54,701 714 0.01305 6,300 87 0.01381

2007 41,883 1,332 0.03180 56,886 761 0.01337 7,211 115 0.01594

2008 36,567 935 0.02556 57,480 663 0.01153 7,259 95 0.01308

2009 29,729 561 0.01887 60,630 623 0.01027 6,497 60 0.00923

2010 45,476 764 0.01680 66,847 509 0.00761 6,857 57 0.00831

2011 46,746 1,723 0.03685 62,908 486 0.00772 6,941 67 0.00965

Mean 0.02767 0.01266 0.01493

STDEV 0.00686 0.00404 0.00697

As previously explained in “Operational Definitions of Variables,” Random 

“positives” consist of the total number of Random Verified Positive Test Results plus the 

total number of Adulterated, Substituted, “Shy Bladder” with No Medical Explanation, 

and other refusals to submit to testing. The Random positivity rates are obtained by 

dividing those “positives” by the total number of Random tests. The 2003-2011 PreEmployment, Random, and Post-Accident positivity rates from Table 24 are displayed 

graphically in Figure 6.
78

Figure 6 

MIS Pre-Employment, Random, and Post-Accident drug test positivity rates

Crewmembers not passing a Pre-Employment chemical test for dangerous drugs 

are not subject to further testing because they are not hired. Pre-Employment positivity 

rates therefore do not directly affect Random or Post-Accident positivity rates; however, 

the differences in positivity rates between Pre-Employment and Random as well as 

between Pre-Employment and Post-Accident are startling and are unlikely to be 

attributed to chance. The data appear to show that the Pre-Employment drug test 

eliminates those persons whose drug use would appear to be so much a part of their lives

that they are unable to suspend it sufficiently long enough to pass a drug test even with 

advance notice. 

From the tables and histogram, the Random and Post-Accident positivity rates 

appear to have a gradually decreasing trend. That trend is shown graphically in Figure 7 

below. 
79

Figure 7 

Trend Line of Random and Post-Accident positivity rates

The trend in Figure 7 is significant because Random positivity rates are derived 

from a very large sample size of crewmembers eligible for chemical testing as shown in 

Table 24. As shown in Table 25, the yearly sample sizes of Random test results 

represent at least 53% and as much as 63.6% of crewmembers eligible for testing, more 

than a mere sampling of crewmembers subject to Random drug tests. These high 

sampling percentages provide confidence that the Random drug test positivity rates fairly 

represent the level and trend of drug use among commercial vessel personnel subject to 

chemical testing. 
80
81

Table 25 

Percentages of Crewmembers Randomly Tested

ALL VESSELS

 Year Percentage of Crewmembers 

Randomly 

 Tested

2003 56.2

2004 55.7

2005 57.1

2006 61.5

2007 63.6

2008 57.0

2009 53.2

2010 59.7

2011 57.3

Figure 8 shows the Random and Post-Accident positivity rates in a scatter plot.

Figure 8 

Scatter Plot of Random and Post-Accident Positivity Rates

S c atter P lot of MIS R eporting Data

R andom P os itive R ate v. P os t-Ac c ident P os itive R ate

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5

R andom P os itiv e R ate

P os t-A c c ident R ate
82

The Figure 8 scatter plot shows a strong linear relationship between Random 

positivity rates represented by the horizontal or x axis and the Post-Accident positivity 

rates represented by the vertical or y axis. That relationship suggests a regression line as 

shown in the Figure 9 scatter plot. 

The formula for the best-fitting regression line is y = mx + b where m is the slope 

of the line and b is the y-intercept. The x values are the Random positivity rates and the y

values are the Post-Accident positivity rates. The slope of a line is the change in y values 

over the change in x values. The y intercept is the point on the y axis where the x value is 

zero. Applying the LINEST formula in EXCEL® yields a slope of 1.632. Applying the 

INTERCEPT formula in EXCEL® yields -0.572 as the y intercept. The best fitting 

regression line (y = mx + b) for the Random and Post-Accident positivity rates from 

Table 17 is depicted in Figure 9 on the next page. 
83

Figure 9 

Scatter Plot and Regression line for Random versus Post-Accident positivity 

rates

The regression line shows that within the range of values for which there is data 

(2003-2011) there is a very straight linear relationship between Random and PostAccident positivity rates. The regression line also shows Random drug test positivity is a 

fairly accurate predictor of Post-Accident drug test positivity. Once the Random rate 

approaches zero, the line may no longer be linear; therefore, this study does not make any 

predictions of Post-Accident positivity rates based on Random positivity rates that are not 

part of the data. Further, there appears to be a strong correlation between Random and 

Post-Accident drug test positivity rates. Applying the CORREL formula in EXEL® to 

the 2003-2011 Arrays of Random and Post-Accident drug test positivity rates from Table 
84

24, the correlation coefficient is 0.94642525, showing a strong, linear relationship. It is 

sufficient to conclude that decreasing Random positivity rates have, on the average, 

predicted decreasing Post-Accident positivity rates at least from 2003-2011. Lower PostAccident positivity rates results in fewer serious marine incidents with drug involvement, 

thereby enhancing the safety of the maritime transportation industry at least to the extent 

of fewer positive drug tests per serious marine incident. 
85

XI. DISCUSSION

A. SUMMARY

Research question number one is “[t]o what extent, if any, has chemical testing 

discouraged drug and alcohol use by commercial vessel personnel.” In response to that 

research question, this study showed yearly 2003-2011 Post-Accident drug test positivity 

rates from small passenger vessel crewmembers were significantly lower than 

corresponding Post-Accident drug test positivity rates from commercial fishing vessel

crewmembers. The difference between the two categories is small passenger vessel 

crewmembers are subject to comprehensive chemical testing and commercial fishing 

vessel crewmembers are not subject to comprehensive chemical testing except for PostAccident drugs and alcohol. Comprehensive chemical testing includes Pre-Employment, 

Random, Reasonable Cause, and Post-Accident. The positivity rate differences are 

statistically significant and not due to chance; therefore, I rejected the null hypothesis that 

there is no difference in Post-Accident drug test positivity rates between the two 

categories. 

This author expected Post-Accident positivity rates for small passenger vessel 

crewmembers to be less than those of commercial fishing vessel crewmembers because 

experiences with the military’s drug testing program showed random testing to be an 

effective deterrent. The Mehay and Pacula (1999) study corroborates this expectation. 

Using 1995 data from the National Household Survey of Drug Abuse (NHSDA) and the 

Department of Defense’s Worldwide Survey of Drug Abuse (DODWWS), Mehay and 

Pacula (1999) examined the deterrence effect by comparing differences in illicit drug use 
86

between the military and the civilian populations. They found the military’s strict antidrug program to be highly effective in deterring illicit drug use to the extent drug 

participation in the military ranged between 4% and 16% lower than in the civilian 

sector, depending on the age group. It was reasonable to assume the commercial vessel 

personnel chemical drug and alcohol testing program would show crewmembers subject 

to chemical testing have a lower positivity rate than crewmembers not subject to 

chemical testing. I was surprised to see that the differences in Post-Accident positivity 

rates between small passenger vessel crewmembers were at least 32% (2008) and as 

much as 96% (2009) lower than Post-Accident drug test positivity rates of commercial 

fishing vessel crewmembers. Small passenger vessel crewmembers subject to 

comprehensive chemical testing had a 2003-2011 average of 77% fewer Post-Accident 

positive drug tests than commercial fishing vessel crewmembers not subject to 

comprehensive chemical testing. That is substantially more than a 4% to 16% difference 

between the military and civilian populations. 

Also in response to research question number one, this study showed yearly 2003-

2011 Post-Accident alcohol test positivity rates from SPV crewmembers subject to 

comprehensive chemical testing were significantly lower than yearly 2003-2011 PostAccident alcohol test positivity rates from CFV crewmembers not otherwise subject to 

chemical testing except for Post-Accident drugs and alcohol. The overall differences in 

Post-Accident alcohol test positivity rates are statistically significant and not due to 

chance; therefore, I rejected the null hypothesis that there is no difference in PostAccident alcohol test positivity rates between the two categories. 
87

I did not expect to see the differences in Post-Accident alcohol test positivity rates 

of SPVs to be at least 14% (2007) and as much as 100% (2006, 2008, and 2010) lower 

than Post-Accident alcohol test positivity rates of CFV crewmembers. SPV 

crewmembers subject to comprehensive chemical testing had a 2003-2011 average of 

72% fewer Post-Accident positive alcohol tests than CFV crewmembers not subject to 

comprehensive chemical testing. This author expected lower alcohol test positivity rates 

but did not expect that the differences would be this large and statistically significant. 

This is especially so because the Coast Guard does not mandate Pre-Employment, 

Periodic, or Random alcohol testing. However, crewmembers are subject to Reasonable 

Cause tests for alcohol as prescribed in 33 C.F.R. pt. 95. Credentialed crewmembers 

testing positive for alcohol use under that part also face suspension and revocation 

proceedings in addition to any personnel actions their employers impose. 

Another reason for large differences in positivity rates may be due to credentialed 

crewmembers potentially facing suspension and revocation proceedings if they are 

convicted of operating a motor vehicle while under the influence of alcohol. Driving 

While Intoxicated or Driving Under the Influence are offences described in the National 

Driver Register Act, 49 U.S.C. 30304(a)(3)(A), and violations therefore would constitute 

a wrongful violation of 46 U.S.C. § 7703(3). These deterrents, plus being subject to 

comprehensive chemical testing for drugs, would appear to account for the large 

differences in alcohol positivity rates between commercial fishing vessel crewmembers 

and small passenger vessel crewmembers. 

In final response to research question number one, this study showed yearly 2003-

2011 Post-Accident drug test positivity rates of all crewmembers subject to 
88

comprehensive chemical testing from all vessels were substantially lower than positivity 

rates of CFV crewmembers not subject to comprehensive chemical testing except for 

Post-Accident drugs and alcohol. The differences in Post-Accident drug test positivity 

rates between the two categories are statistically significant and not due to chance; 

therefore, I rejected the null hypothesis that there is no difference in Post-Accident drug 

test positivity rates between the two categories. 

This author was surprised to learn the differences in Post-Accident positivity rates 

between the two categories of crewmembers were at least 89% lower (2008) and as much 

as 97% lower (2009) than Post-Accident drug test positivity rates of commercial fishing 

vessel crewmembers not subject to comprehensive chemical testing. All vessels with 

crewmembers subject to comprehensive chemical testing had a 2003-2011 average of 

92% fewer Post-Accident positive drug tests than commercial fishing vessel 

crewmembers not subject to comprehensive chemical testing. These results were also 

surprising because it appeared SPVs would be the safest of all vessels with crewmembers 

subject to chemical testing. Upon further consideration, small passenger vessels 

ordinarily would be underway more often than other vessels because they are carrying 

passengers on regular schedules exposing those vessels to the hazards of navigating in 

close quarters with frequent trips involving docking and undocking. The results show all 

vessels with crewmembers subject to chemical testing, including SPVs, have even lower 

Post-Accident drug test positivity rates than SPVs exclusively. 

Crewmembers subject to comprehensive chemical testing generally have much 

more to lose than crewmembers on CFVs. A positive drug test will generally result in 

loss of employment, at least in a safety sensitive position, as well as loss of credentials. 
89

As pointed out in Mehay and Pacula (1999), facing job loss would appear to deter use of 

dangerous drugs as well as alcohol. 

I expected crewmembers not subject to comprehensive chemical testing except for 

Post-Accident would have higher positivity rates in both drugs and alcohol than 

crewmembers not subject to chemical testing. Not being subject to comprehensive 

chemical testing except for Post-Accident drugs and alcohol coupled with the inherent 

dangerousness of commercial fishing would also seem to result in higher drug and 

alcohol positivity rates. The inherent dangerousness of commercial fishing is also more 

likely to attract crewmembers that are more inclined to embrace risk and possibly engage 

in risky behavior, including drugs and alcohol, compared to crewmembers of small 

passenger vessels or other vessels with crewmembers subject to chemical testing.

Research question number two is “[t]o what extent, if any, does chemical testing 

reduce the potential for marine casualties related to drug and alcohol use.” In response to 

that question this study showed yearly 2003-2011 ratios of Post-Accident positive drug 

tests per SMI from SPV crewmembers subject to chemical testing are substantially lower 

than corresponding Post-Accident positive drug tests per SMI from CFV crewmembers 

not otherwise subject to chemical testing. The differences in Post-Accident positive drug 

tests per SMI between the two categories are statistically significant and not due to 

chance; therefore, I rejected the null hypothesis that there are no differences in positive 

drug tests between the two categories.

This author was surprised to learn the differences between the two categories of 

crewmembers were at least 20% (2006) and as much as 96% (2009) lower for small 

passenger vessel crewmembers. I knew small passenger vessel crewmembers subject to 
90

comprehensive chemical testing would have fewer Post-Accident positive drug tests per 

serious marine incident but I did not know that the differences would average 71%. This 

is especially so because fewer drug related accidents may not necessarily be directly 

attributed to drug testing but might have occurred due to other improvements in safety, 

even in the absence of drug testing (Rothstein, 1991). However, with differences this 

large and statistically significant, being subjected to Pre-Employment, Random, and 

Reasonable Cause chemical testing would appear to be major influences in those 

differences.

In further response to research question number two, this study showed yearly 

2003-2011 ratios of Post-Accident positive alcohol tests per serious marine incident from 

small passenger vessel crewmembers subject to chemical testing are substantially lower 

than corresponding Post-Accident alcohol tests per serious marine incident from 

commercial fishing vessel crewmembers not otherwise subject to chemical testing. The 

differences in Post-Accident positive alcohol tests per serious marine incident between 

the two categories are statistically significant and not due to chance; therefore, I rejected

the null hypothesis that there are no differences in positive alcohol tests between the two 

categories. 

For the reasons expressed above concerning the differences in alcohol tests 

between the two categories, this author was surprised to learn that Post-Accident positive 

alcohol tests per SMI were at least 8% (2007) and as much as 100% (2006, 2008, and 

2010) lower for SPVs from 2003-2011. SPV crewmembers subject to comprehensive 

chemical testing had a 2003-2011 average of 73% fewer Post-Accident positive alcohol 

tests per SMI than CFV crewmembers not subject to comprehensive chemical testing. 
91

Also, for the reasons expressed above concerning positive drug tests per SMI, fewer 

alcohol related accidents may not necessarily be directly attributed to alcohol testing but 

might have occurred due to other improvements in safety, even in the absence of alcohol 

testing (Rothstein, 1991). However, with differences this large and statistically 

significant, being subjected to Pre-Employment, Random, and Reasonable Cause 

chemical testing as well as the alcohol testing requirements of 33 C.F.R. pt. 95 and the 

threat of suspension and revocation proceedings for violations of the National Driver 

Register Act, 49 U.S.C. 30304(a)(3)(A) would appear to contribute to the differences.

Research question number three is, “[t]o what extent, if any, does chemical

testing enhance the safety of the maritime transportation industry.” In response to 

research question number three this study showed a strong linear relationship between 

yearly 2003-2011 Post-Accident drug test positivity rates from all vessels with 

crewmembers subject to chemical testing and decreasingly lower Random drug test 

positivity rates for 2003-2011 from all vessels with crewmembers subject to chemical 

testing; therefore, I rejected the null hypothesis that there is no strong correlation or linear 

relationship between Random and Post-Accident positivity rates. 

This author was aware that Pre-Employment, Random, and Post-Accident 

positivity rates were gradually trending downward by simply observing the year after 

year positivity rates. These downward trends are also consistent with the Quest 

Diagnostics Drug Testing Index (2012) and the 2008 DOD Survey of Health Related 

Behaviors Among Active Duty Military. I knew there was a moderate to strong 

correlation between Random and Post-Accident drug test positivity rates but was 
92

surprised to learn there was also a linear relationship showing Random positivity rates to 

be a good predictor of Post-Accident positivity rates. 

As discussed above, Pre-Employment drug tests screen out most dangerous drug 

users. Those remaining are aware they are subject to an unannounced Random test, a 

Reasonable Cause test, and, if there is a serious marine incident, a Post-Accident drug 

and alcohol test. As shown graphically in the Figure 6 histogram, it stands to reason that 

those remaining crewmembers would avoid using dangerous drugs compared to those 

subject to the Pre-Employment test. 

B. CONCLUSIONS

Through secondary data analysis of archived test results, this author examined the 

extent chemical testing has discouraged drug and alcohol use by commercial vessel 

personnel, reduced the potential for marine casualties related to drug and alcohol use, and 

enhanced the safety of the maritime transportation industry. To determine the extent 

chemical testing has discouraged drug and alcohol use, I examined Post-Accident drug 

and alcohol positivity rates from two groups of commercial vessel personnel. One group 

had been subject to chemical testing and the other group had not except for Post-Accident 

drugs and alcohol. The results showed Post-Accident drug and alcohol positivity rates 

from the group subject to chemical testing was significantly lower than those from the 

group not subject to chemical testing except for Post-Accident. 

The results also show the extent to which chemical testing has the potential to 

reduce marine casualties related to drug and alcohol use because the group subject to 

chemical testing had significantly fewer Post-Accident positive drug and alcohol tests per 
93

serious marine incident than the group not subject to chemical testing, except for PostAccident.

 Finally, these results illustrate the extent to which chemical testing has the potential 

to enhance the safety of the maritime transportation industry. These results showed a

strong correlation between Random and Post-Accident drug test positivity rates. Further,

a linear regression analysis demonstrated Random positivity rates to be a fairly accurate 

predictor of Post-Accident positivity rates. Maritime transportation safety is enhanced to

the extent of fewer positive chemical tests per serious marine incident. 

A. RECOMMENDATIONS

These results suggest chemical testing might discourage drug and alcohol use, 

reduce the potential for marine casualties, and enhance the safety of the maritime 

transportation industry. Routine and wide dissemination of these results to the maritime 

community could further enhance the safety of the maritime transportation industry. 

Dissemination could simply take the form of displaying positivity rate trends and PostAccident positive drug and alcohol tests per SMI. 

Future studies can encompass crewmembers of all vessel types as well as 

crewmembers of specific vessel categories. Researchers could include specific drugs 

(e.g., marijuana, cocaine, PCP, opiates, and amphetamines) and examine the trends in 

that drug’s use as well as the number of positive tests of that drug per SMI in which tests 

are reported for crewmembers of specific vessel categories. A researcher could also use 

questionnaires in future studies. Questionnaires designed to ensure anonymity can be 

made available to commercial vessel personnel at the time they renew their Credentials. 

The questions can inquire into similar acts and practices as those asked in “Department of 
94

Defense Surveys of Health Related Behaviors Among Active Duty Military” but focus on 

acts and practices that relate to vessel safety. 

This study showed statistically significant differences in Post-Accident positivity 

rates and positive tests per serious marine incident between small passenger vessel 

crewmembers and commercial fishing vessel crewmembers. It also showed Random 

drug tests are good predictors of Post-Accident tests. When combined with current 

initiatives to enhance commercial fishing vessel safety (Dickey, 2012), comprehensive 

chemical testing of commercial fishing vessel crewmembers could help reduce the 

potential for marine casualties related to drug and alcohol use and enhance fishing vessel 

safety. 
95

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