The Value of PORTS® to the Nation

How Real-time Observations Improve Safety and Economic Efficiency of Maritime Commerce

National Oceanic and Atmospheric Administration

U.S. Department of Commerce
Cover: Large container vessel transiting under the Gerald Desmond Bridge in Los Angeles, California. Credit: Warren Krug, NOAA 

Inside cover: Air gap installation on Dames Point Bridge in Jacksonville, Florida. Credit: Steve O’Malley, Ocean Tech Services, LLC
Our lives depend on maritime commerce

http://tidesandcurrents.noaa.gov/ports.html

id you know that the majority of products that Americans find on store 

shelves come to us by way of the United States marine transportation 

system? It is the backbone for the movement of goods, services, and people 

throughout the nation and abroad. Like most infrastructure systems, the 

nation’s network of waterways and seaports is challenged by ever increasing 

demand. Continually larger ships are pushing the limits of existing navigation 

channels and bridge heights at seaports. In addition, the volume of traffic at 

U.S. seaports is expected to double by 2021, and double again shortly after 

2030.

Bigger vessels and greater traffic means increased potential for accidents. 

Over 600 commercial vessels annually are involved in accidents on the nation’s 

waterways and major seaports. Real-time observations from PORTS®, or the

Physical Oceanographic Real-Time System, when combined with up-to-date 

nautical charts and precise positioning, can greatly increase the safety and 

efficiency of maritime commerce. For example, there has been a nearly 60 

percent reduction in groundings at some seaports currently served by PORTS®.

This document communicates the results of an economic valuation conducted 

by NOAA that estimated as much as a $300 million annual benefit from 

an expanded PORTS® system serving the nation’s 175 major seaports; the 

potential ten-year net present value of this investment could be as much as 

$2.5 billion. PORTS® is a key element of the informational infrastructure that 

improves the safety and efficiency of the U.S. marine transportation system, 

and our continuing ability to successfully compete in the expanding global 

economy.

Sincerely,

Richard Edwing

Director, Center for Operational Oceanographic Products and Services (CO-OPS)

NOAA National Ocean Service

D

Percent of all trade involving some form 

of marine transportation 

In 2008, approximate dollars contributed 

to our gross domestic product from 

marine transportation

Jobs supported by marine transportation

Miles of waterways, seaports, and other 

commercially navigable waters 

Number of marine terminals

76%

$740 billion

13 million

15,000

3,700+

1

The following statistics show the importance of U.S. 

waterborne transport in recent years:
On the morning of May 

9, 1980, a freighter ship, 

the Summit Venture, was 

heading from the Gulf 

of Mexico up Tampa Bay 

to the Port of Tampa. 

The weather conditions 

on this particular day 

were treacherous, with 

tropical storm force 

winds and heavy rain. 

With near zero visibility, the ship lost its radar, rendering it essentially 

blind as it approached a critical bend in the route leading between 

the two main piers of the Sunshine Skyway Bridge.

High winds and currents pushed the 20,000 ton freighter out of the 

channel, and when the freighter hit the bridge’s main support pier, 

the suspended roadway above fell 150 feet into the water. Six cars, a 

truck, and a Greyhound Bus fell, killing 35 people. Only one person 

that fell from the bridge survived.

U.S. Coast Guard inquiries following this tragedy determined that 

the use of real-time oceanographic and meteorological information 

may have helped to avoid this accident. In 1991, in response to this 

incident and other maritime accidents, the Physical Oceanographic 

Real Time System, or PORTS®, was established to provide accurate 

and reliable real-time information about environmental conditions in 

seaports. Today, PORTS® serves about one-third of all major seaports 

in the United States.

Why PORTS®? What if one major accident is avoided?

A tragic bridge collapse One maritime accident can cost tens of millions of dollars

Many maritime accidents have minor impacts, but others have 

been catastrophic. For these catastrophic events, avoiding just 

one accident can save tens or even hundreds of millions of dollars 

in property damage, oil spill response, injuries to our coastal 

environment, port facility closures, and the potential for loss of life. 

The trend towards bigger vessels and greater port traffic will result in 

increased potential for accidents. An investment in PORTS® provides 

the real-time data and decision-support tools that can help mariners 

and port operators avoid maritime accidents.

2

Scene from the Sunshine Skyway Bridge collapse in May, 1980. 

Credit: St. Petersburg Times

Ship entering Tampa Bay under the Sunshine Skyway Bridge. Credit: Mike Henderson

Ship entering a berth at Tampa Bay harbor. Credit: Mike Henderson
What is PORTS®?

PORTS® is an integrated system of oceanographic and 

meteorological sensors that provide mariners with 

accurate and reliable real-time information about 

environmental conditions in seaports. In concert with 

nautical charts and other navigational aids, this “coastal 

intelligence” helps mariners make better safety and 

economic decisions. 

With PORTS®, mariners can access observations and 

predictions of water levels, currents, waves, salinity, 

water temperature, bridge heights, winds, visibility, 

atmospheric pressure, and air temperature – information 

that is critical to safe navigation. All PORTS® observations 

and predictions are quality controlled by NOAA 24 hours 

a day, 365 days a year. 

Systems come in a variety of sizes and configurations, 

each specifically designed to meet local user 

requirements. The largest existing PORTS® installation 

is comprised of over 100 individual sensors, while the 

smallest consists of a single water level sensor and 

associated meteorological sensors. Regardless of its size, 

each PORTS® provides real-time information to improve 

both the safety and efficiency of maritime commerce 

based on needs identified by local users.

“I can’t imagine doing my job without PORTS®!” 

- Captain Jon Kemmerley, Delaware Bay and 

 River Pilot

Elevated tide station with wind sensors. 

Credit: CO-OPS

Real-time, accurate, and reliable PORTS®

3

Visibility sensor at Pinto Island on Mobile Bay is primarily used to 

determine fog on the waterway. Credit: CO-OPS
Where is PORTS®? PORTS® currently serves about one-third of the 175 major seaports in the U.S. 

Percent of 175 major seaports 

currently served by PORTS®.

Percent of depth constrained total tonnage that passes 

through seaports currently served by PORTS®.

34% 75%

Major U.S. Seaport

Major U.S. Seaport Served by PORTS®

4
How does PORTS® help mariners?

“We are convinced 

that, because of the 

PORTS® system, a 

potential grounding 

was avoided.”

 - Ted Lee,

 NSA Agencies, Inc.

PORTS® real-time observations are updated at sixminute intervals and are available via the Internet 

and via toll-free phone calls. PORTS® information is 

also available on mobile devices, making it even more 

convenient for both commercial and recreational users 

to access real-time data anytime, anywhere.

PORTS® provides benefits beyond the maritime 

community. When hurricanes strike or there is an oil 

spill, local emergency response personnel use wind 

and currents data from PORTS® to inform decisionmaking. Water level data from PORTS® also supports 

local decision-making, as in the case of the Domino 

Sugar Plant in Baltimore, where PORTS® is monitored 

to help decide when to shut the plant down due to risk 

of flooding. Similarly, New York City monitors PORTS®

data to help decide when to shut down certain subway 

air intakes due to risk of flooding. PORTS® data has also 

been used to improve local habitat restoration efforts 

by providing tidal datums, frequency of inundation 

projections, and sea level trends.

http://tidesandcurrents.noaa.gov/ports.html

NOAA monitors the quality of PORTS ® 

data 24 hours a day, seven days a week, 

365 days a year. Credit: CO-OPS

“It’s very, very valuable information. We run 

a lot of deep-draft vessels in and out of here. 

Having that accurate information also enables 

ships to put on just a little bit more cargo if we 

do have a good positive tide.” 

- James Lyon, Director and Chief Executive 

 Officer at the Port of Mobile, on PORTS®

Both mariners and seaport operators use PORTS® realtime information to maintain an adequate margin of 

safety for increasingly larger vessels in more congested 

seaports. Safety and efficiency are inextricably 

linked and a safer seaport is a more efficient 

seaport. Both mariners and seaport operators use 

PORTS® to maximize seaport throughput. Real-time 

observations help to optimize use of the available 

water column and to plan the most efficient transit 

scheduling and loading operations. One additional inch 

of draft may account for several millions of dollars in 

cargo value per transit.

5

Other essential uses of PORTS® information

A safer seaport is a more efficient seaport

Real-time data available anytime, anywhere
Improving safety through air gap technology

As commercial vessels have grown in size, bridge clearance 

at our nation’s seaports has become a more significant safety 

concern and can limit seaport operations. In response, NOAA 

researched, tested, and installed the first air gap sensor in 2004, 

on the Reedy Point Bridge in Maryland, to provide real-time 

information on bridge clearance. Since then, at the request 

of mariners and seaport operators, this technology has been 

successfully deployed at PORTS® serving nearly a dozen 

seaports. 

The integration of air gap sensors into PORTS® demonstrates 

NOAA’s ability to adapt to emerging issues, and evolve PORTS® 

to meet specific needs of users for improved safety. As part 

of its larger PORTS® program, NOAA is continually testing and 

evaluating new technologies, in order to make existing services 

more accurate and reliable, but also to provide new services 

that will improve the safety of vessel traffic and seaport 

operations. In support of the ports of Los Angeles and Long 

Beach, NOAA quickly installed an air gap sensor to allow the 

first of a new super class vessel to access the seaport.

PORTS® can readily evolve to address emerging 

safety issues What is air gap?

Real-time observations of 

the distance between the 

lowest point of a bridge 

and the surface of the 

water enables mariners 

to make a critical safety 

decision: 

Can my vessel pass 

safely under this 

bridge?

Air gap installation on Dames Point Bridge in Jacksonville, Florida. 

Credit: Steve O’Malley, Ocean Tech Services, LLC

6

“We use air gap data from the Bayonne Bridge 

and water level data from the Bergen Point water 

level gauge to bring vessels within two feet of 

the bridge and two feet from the bottom at the 

same time!” 

 - NY Metro Pilots
More Efficient Commercial Marine Transportation

Enhanced Fishing Productivity

Commercial Fishing

Recreational Fishing

What if PORTS® served all major U.S. seaports?

Benefit Area Potential Annual Value

$265.5

Reduced Commercial Marine Transportation Accidents

Property Damages

Injuries and Deaths

Reduced Recreational Boating Accidents

Property Damages

Injuries and Deaths

Reduced Oil Spill Remediation

Improved safety

Real-time observations from 

PORTS® can greatly increase 

safety. At seaports currently 

served by PORTS®, there has 

been a significant reduction 

in maritime accidents. 

Increased efficiency

PORTS® enables mariners 

to safely use every inch of 

available channel depth, 

thereby increasing the 

amount of cargo moved per 

transit. One additional inch 

of draft may account for 

several millions of dollars in 

cargo value per transit.

Potential Ten-Year 

Net Present Value

$1.8

$0.3

$5.2

$2,172.3

$42.3

Increased Efficiency

Improved Safety

$7.7

$19.1

<$0.1

$0.4

$15.1

$2.5

$64.4

$156.3

<$0.1

$3.1

Total $300.0 $2,456.0

7

PORTS® currently serves about one-third of the 175 major U.S. seaports, and NOAA has identified and 

estimated the value of specific safety and efficiency benefits realized at several of these operational 

PORTS®. Building on these case studies of actual benefits, NOAA has estimated as much as a $300 

million annual benefit from an expanded PORTS® system serving all 175 major U.S. seaports.

Potential Value of an Expanded PORTS® System Serving 175 Major U.S. Seaports

Potential value of a fully-built PORTS® system

(Millions of 2010 dollars)

(Ten-Year Net Present Value is the sum of discounted benefit values for the next 10 years.)
Reduced Commercial Marine Transportation Accidents

Commercial Marine 

Transportation in the U.S.

Existing PORTS® Have Improved 

Commercial Marine Transportation Safety

Potential Value of an 

Expanded PORTS® System

Potential value of reduced 

commercial marine 

transportation accidents from 

PORTS® serving 175 major U.S. 

seaports.

Safety is paramount to the maritime community. As the number and size 

of cargo vessels, cruise ships, and other commercial vessels visiting U.S. 

seaports increases, so does the risk of accidents. In locations where PORTS®

real-time observations have been available to mariners and seaport operators, 

collisions and groundings have been reduced.

Accidents have been reduced at seaports currently served by PORTS®.

Collisions and Groundings

Groundings

(33% when groundings are combined with collisions)

Property damage

Injuries

Deaths

59%

37%

45%

60%

Benefit Area

Property

Damages $7.7

Injuries and 

Deaths $19.1

Total $26.8

10 Year Net 

Present Value $220.7

Improved Safety

Improved Commercial Marine Transportation Safety

Cranes use PORTS® air gap information while 

passing under the Crescent City Bridge in New 

Orleans, Louisiana. Credit: Port of New Orleans

Potential 

Annual Value

(million)

PORTS® information is used in “go–no go” decisions, to determine if vessels are allowed to proceed to dock or anchored to avoid grounding.

Distribution of Property 

Damage for all Accident Types

Vessel Damage

Facilities Losses

Cargo Losses

Losses by Third Party 

Entities

53%

33%

2%

12%

8

“The MAC uses PORTS® data to help prevent and/or recover from damage to our 

port complex. In 2011’s Hurricane Irene, the Coast Guard and MAC used PORTS® 

information to manage shipping traffic in the river above Philadelphia during 

the post storm period when tides were running far above normal, preventing the 

possibility of hitting bridges or causing damage to other critical infrastructure.”

 - Captain Steve Roberts, Chairman, Mariners Advisory Committee for 

 the Bay and River Delaware (MAC) 
9

Improved Safety

Reduced Recreational Boating Accidents

Recreational Boating 

in the U.S.

PORTS® Can Be Used to Reduce 

Recreational Boating Accidents

Potential Value of an 

Expanded PORTS® System

Potential value of reduced 

recreational boating accidents 

from PORTS® serving 175 major 

U.S. seaports.

Real-time observations and predictions provided by PORTS® can be used by 

recreational boaters to better understand environmental conditions prior 

to and during their trip. Specifically, PORTS® can be used to gain a good 

understanding of timing and magnitude of tides, currents, and winds, thereby 

reducing accidents caused by weather and groundings.

There were 850 recreational boating accidents from 2005 to 2012 that 

were caused by weather and groundings. Conservative estimates show 

that PORTS® serving 175 major U.S. seaports could help to reduce the 

property damage, injuries, and deaths resulting from such accidents.

Weather Groundings 

Propery Damage

Injuries

Deaths

Propery Damage

Injuries

Deaths

$2.5 mil

120

32

$14 mil

336

17

Benefit Area

Reduced

Groundings $40,000

Reduced 

Weather 

Losses

$339,000

Total $380,000

$3.1 million Percent of recreational 

boaters in coastal states.

Percent of recreational 

boaters operating out 

of one of the 175 major 

seaports.

12.2 million

Approximate number of 

recreational boats in the United 

States in 2011. This is greater 

than the population of the state 

of Ohio.

Recreational boating accounts for 13 percent of all recreational expenditures in the U.S.

Both the recreational boating community and the recreational fishing 

community use PORTS® before leaving the dock to check weather, times of 

high and low water, and timing and velocity of currents. This helps mariners 

ensure a safe boating experience. Sailboat and yacht clubs use PORTS® to help 

ensure the safety of their water-based events. 

Improved Recreational Boating Safety

32%

Percent of adults in the United 

States that participate in 

recreational boating.

A NOAA water level gauge is used to measure 

tides. Credit: CO-OPS

Potential 

Annual Value

54%

45%

10 Year Net 

Present Value
Reduced Oil Pollution Remediation

Pollution Spills 

in the U.S. Existing PORTS® Reduced Accidents and Associated Oil Spills

In locations where PORTS® real-time observations have been available, oil 

releases due to collisions and groundings have been reduced by 21 percent. 

Oil spill remediation is a costly endeavor. Oil spill events can cause long 

disruptions in seaport and waterway operations and cause environmental 

damage.

Oil spills have been reduced at seaports currently served by PORTS®.

Oil Spills

Benefit Area

Property

Damages $5.2

Total $5.2

$42

Improved Safety

All Pollution Spills

Petroleum Spills

Percent of spill occurrences

involving the release of any 

pollutant that are greater than one 

gallon. 

Percent of spill occurrences

involving the release of more than 

one gallon of petroleum products.

Reduction in oil releases due to collisions and 

groundings at seaports currently served by PORTS®.

21%

“.... in 1993, a 634-foot tanker, Potomac 

Trader, while maneuvering in the New 

York harbor using “predicted Tides 

Tables” ran aground in Hells Gate. Had 

the tanker had access to a real-time 

NOAA PORTS®, this near-disaster could 

have been averted. The vessel master 

would have obtained information 

about an abnormally large tidal range 

that caused the actual tide to be three 

feet lower than the predicted tide. 

Fortunately, the vessel was a doublehull tanker and none of its cargo of 

over seven million gallons of crude oil 

spilled.”

- United States Coast Guard

NOAA’s Office of Response and 

Restoration (OR&R) uses real-time 

information on winds, currents, 

visibility, water levels, waves, and 

salinity when responding to spill 

events. This information is used 

for the containment and clean-up 

as well as to plan for restoration 

efforts. In other words, PORTS® 

information can help OR&R locate 

and remediate such spills. NOAA 

responds to about 104 of the 

largest spill events annually.

 

- NOAA’s Office of Response 

 and Restoration

Spill Prevention Spill Containment and Clean-up

Total remediation cost for one barrel of oil is $10,700. That is over $250 for every gallon spilled.

Vessels waiting for the MIssissippi River to 

reopen after a collision of two barges caused an 

oil spill. Credit: NOAA

96%

46%

Potential 

Annual Value

(million)

10

Potential Value of an 

Expanded PORTS® System

Potential value of reduced oil 

spill remediation at PORTS® 

serving 175 major U.S. seaports.

10 Year Net 

Present Value
Increased Efficiency

More Efficient Commercial Marine Transporation

Potential value of more efficient 

commercial marine transportation 

from PORTS® serving 175 major 

U.S. seaports.

PORTS® real-time observations and forecasts allow mariners to

optimize use of available water depth by adjusting cargo load and/or transit 

schedules. More cargo carried per transit means lower transportation cost 

per ton. Similarly, reducing vessel transit delays can lower transportation 

costs per ton.

Clearance Parameters 

when Entering a Seaport

Existing PORTS® Increase the 

Efficiency of Marine Transportation

Benefit Area

Added 

Shipping 

Costs

$117.4

Extra 

Handling $36.5

Total $265.5

$2,172.3

Air Gap Clearance

Under Keel Clearance

The distance between the top of 

the ship and the lowest point of 

a bridge. 

The distance between the ship’s 

keel and the bottom of the 

channel. 

Smaller safety margins for 

under keel clearance and air 

gap clearance.

Greater safety and efficiency 

of marine transportation.

=

Why is this important?

Injury and 

Death $6.4

Improved Efficiency

A liquified natural gas vessel entering 

Sabine, Texas. Credit: NOAA

The average size of commercial vessels increased 12 percent from 2002 to 2005.

Reducing Under Keel Clearance Restrictions

Improved Transit Times

Reduced 

Delays in 

Transit

$105.2

Estimated average savings per vessel transit by 

using real-time information from the existing 

PORTS® System.

$1,800

Estimated fewer number of vessel transits by 

reducing under keel clearance restrictions from four 

feet to two feet by using real-time information from 

the existing PORTS® System.

~1,400

“When we load, we call the voice system to see what the water level is doing. Every 

inch of draft is equal to 237 long tons (on the Lake Carrier Edgar B. Spear). When 

we get closer to the Soo (locks) we call again. We use it (PORTS® at Sault Ste. Marie, 

Michigan) a lot and it’s been invaluable. ” 

 - Master of the Edgar B. Spear

Potential 

Annual Value

(million)

11

Potential Value of an 

Expanded PORTS® System

10 Year Net 

Present Value
Enhanced Fishing Productivity

Existing PORTS® Helps Recreational and 

Commercial Fishing Productivity

Potential value of enhanced 

fishing productivity from 

PORTS® serving 175 major U.S. 

seaports.

The availability of PORTS® information helps increase the efficiency of both 

commercial and recreational anglers fishing within three miles of the shore. The 

real-time and forecast oceanographic and meteorological characteristics provided 

by PORTS® help anglers better understand the location and feeding activity of 

targeted species. 

Increased Efficiency

Benefit Area

Recreational

Fishing $0.3

Commercial

Fishing $1.8

Total $2.1

$17.6

Recreational Fishing

Anglers fishing from 

the shore, private/rental 

boats, and charter boats.

Commercial Fishing 

Anglers catching finfish and 

shellfish for commercial 

profit.

Real-time PORTS® observations indicate 

fishing conditions by:

tides and water levels • currents 

• meteorological data • water 

temperature • salinity

Enhanced Fishing

Chesapeake Bay crab fishermen check PORTS® to determine water conditions, 

currents, tides, and weather before beginning their day’s operations. This helps to 

ensure safe and optimized vessel operations.

Fishing in the U.S.

PORTS® current meter installed on a U.S. 

Coast Guard buoy on the Chesapeake Bay. 

Credit: CO-OPS

10 million

Number of anglers that 

made approximately 69 

million marine recreational 

fishing trips in 2011.

29%

Percent of fish that were 

caught by recreational 

anglers within three miles 

from shore (from 2006-

2011).

$1.3 trillion

Approximate value of 

commercial finfish catch in 

2010.

41%

Percent of the value of 

commercial fishing that 

comes from within three 

miles of the shore (average 

from 2005-2011).

Q. What should a fisherman check before leaving seaport? A. Weather, times of high and low water, and current velocity.

Potential 

Annual Value

(million)

12

Potential Value of an 

Expanded PORTS® System

10 Year Net 

Present Value
13

About the Data

Benefit Area Confidence Level 

of Valuation

This document communicates the results of an economic 

valuation conducted by NOAA to estimate the potential value of 

safety and efficiency benefits provided by a fully-built PORTS® 

system serving all of the nation’s 175 major seaports. Economic 

valuation is not an exact science, and NOAA made many 

assumptions; however, in all cases NOAA made conservative 

assumptions. The table below conveys NOAA’s overall confidence 

level for each of the five major benefit areas in this economic 

valuation. The single reference for this document is the economic 

valuation report, which can be downloaded here: 

http://tidesandcurrents.noaa.gov/pub.html

More Efficient Commercial 

Marine Transportation

Enhanced Fishing Productivity

Increased Efficiency

High

Low

Data Sources

Data analyzed in the NOAA economic valuation report came from public, semi-public, and 

private sources.

• NOAA Coastal Services Center’s Digital Coast, Economics: National Ocean Watch 

• National Ocean Economics Program 

• U.S. Army Corps of Engineers’ National Navigation Operation Management Performance 

Evaluation & Assessment System (NNOMPEAS) and Channel Portfolio Tool (CPT) 

• Department of Labor

• Bureau of Labor Statistics

• U.S. Coast Guard

• U.S. Department of Transportation

• Census Bureau’s U.S.A. Trade Online

Other Potential PORTS® Benefits not yet Quantified

The NOAA economic valuation report identified many potential 

benefit areas associated with PORTS®, however, NOAA quantified 

estimated values for only five major benefit areas due to limited data 

for analysis. Other potential benefit areas associated with PORTS® 

include:

Recreation - beach , diving, surfing and kite boarding conditions

Recreational Boating - reduced distress calls, sail conditions

Weather - improved storm surge forecasts

Environmental Restoration - improved habitat restoration planning

Industry - improved marine construction and facility operations

Government - improved public services

Research - additional data for scientific analysis

Reduced Commercial Marine 

Transportation Accidents

Reduced Recreational Boating Accidents

Reduced Oil Spill Remediation

Improved Safety

Medium-High

Medium-High

Medium

Reference

Wolfe, K. Eric and David MacFarland. 2013. An Assessment of the Value of the Physical RealTime System to the U.S. Economy (PORTS®). National Oceanic and Atmospheric Administration. 

Available from http://tidesandcurrents.noaa.gov/pub.html.

Report design, layout, and graphical illustrations by the National Ocean Service’s Communication 

and Education Division.
http://tidesandcurrents.noaa.gov/ports.html