![](media/image1.png){width="2.8751968503937007in"
height="2.872047244094488in"}![](media/image2.png){width="0.8251968503937008in"
height="0.7338582677165354in"}

Contents

[What is Stability? 2](#what-is-stability)

[Definitions 5](#definitions)

[Stability at Work 8](#stability-at-work)

[STABILITY CONDITIONS 10](#stability-conditions)

[Weight Movements 11](#weight-movements)

[Damage Control 12](#damage-control)

[Vessel Stability -- Warning Signs, Precautions
13](#vessel-stability-warning-signs-precautions)

[The Stability Tests 14](#the-stability-tests)

[Stability Tests 16](#stability-tests)

[Minimum Qualifications for Individuals Employed to Conduct Vessel
Stability Testing
18](#minimum-qualifications-for-individuals-employed-to-conduct-vessel-stability-testing)

# What is Stability?

Stability is the tendency of a vessel to rotate one way or the other
when forcibly inclined whether by winds and/or seas so as to resist
capsizing by returning to an upright position after being heeled over.
Many forces influence the stability of a vessel in the water and each
vessel will reacts differently to heeling forces. Vessel operators
should be aware of how the design of their vessel interacts with
external forces of nature and affect its stability. If the vessel was
built and loaded correctly, outside forces may cause the vessel to
temporally roll from side to side, however the vessel will return to the
upright by itself.

A vessel stays afloat by offsetting two forces of nature. The force of
gravity attempts to push the boat down into the water, while the force
of buoyancy of the water will be pushing the hull up. As long as the
buoyancy is greater than the gravity, the vessel will float. How
resistant it is to capsizing is dictated by how these two forces act on
the vessel.

EXAMPLE OF GRAVITY -VS- BUOYANCY

![](media/image4.png){width="0.6972222222222222in"
height="0.6243055555555556in"}
![](media/image5.png){width="1.7902777777777779in" height="0.6875in"}

1 ton of steel 1 ton of steel

If the cube of steel is placed in water it sinks. There is not enough
displaced volume for the forces of buoyancy to act upon. If the cube of
steel is formed into a boat's hull and is placed in the water it will
float. The larger volume of the boat\'s hull allows the forces of
buoyancy to support the hull\'s weight.

The boat\'s hull will sink to a draft where the forces of buoyancy and
the forces of gravity are equal.

**THE LAWS OF BUOYANCY**

1\. All floating objects possess the property of buoyancy.

2\. A floating object displaces a volume of water equal in weight to the
weight of the body.

3\. An object immersed (or floating) in water will be buoyed up by a
force equal to the weight of the water displaced.

**Buoyancy**

The buoyancy of a vessel is determined by the shape of the immersed hull
form. The larger the hull, the more weight it can support. Stability,
however, is dictated by the distribution of that hull volume. For
example, beam has a much larger impact on stability than length. As a
general rule, the wider the hull, the more stable it is. A deeper hull
will also be more stable than a shallow one. The center of buoyancy is
the point at which all the vectors of the floating forces of the hull
can be said to act vertically upward.

The designer usually has a great deal of control of a vessel\'s
stability characteristics while it is still being designed. Good
practice includes designing a stability margin into the hull before the
vessel is built. Unfortunately, features that make a vessel more stable
are often in direct conflict with the other aspects of the design. While
it may be tempting to simply enlarge the beam to increase stability,
this will also increase construction cost as well as increase the
propulsion resistance of the hull. Increased resistance in turn drives
up fuel consumption and operating costs over the life of the vessel. As
with all good designs, a balance between the design criteria and
operational requirements must be reached.

**Weight or Force of Gravity**

The hull, machinery, outfitting, and cargo load determine vessel weight.
As vessel cargo load is increased, the hull will settle deeper in the
water until the buoyancy equals the weight. While this may intuitively
seem to increase stability, adequate

Equally important to the overall weight of the loaded vessel is how that
weight is distributed. The center of gravity is the point at which the
vector of the whole weight of the vessel can be said to act vertically
downward. As a general rule, a lower center of gravity means a more
stable vessel. A vessel with a high center of gravity is said to be
\"top heavy.\" When a vessel lists or heels to one side, the center of
gravity pushes down in the direction of the list.

The vessel weight and center of gravity change constantly as vessel
loading changes. For example, a heavy object placed high on a deck will
produce a higher center of gravity - and less stability - than a load
stored below deck. Similarly, removing a load from low in the vessel,
such as burning fuel oil, will cause an increase in the vessel\'s center
of gravity, thus reducing stability.

Additionally, vessels gain weight over their lifetimes as equipment is
added or other changes are made to the arrangements. A good design will
allow for some weight growth, but careful attention must be paid to
modifications to the vessel to ensure that it continues to meet the
applicable stability requirements.

# Definitions

**Center of Buoyancy** (B) is the point at which all vertical upward
forces (buoyant forces) are said to act. It is the center of the volume
of the immersed portion of the vessel. When a hull is rotated in the
water the center of buoyancy will move as the shape of the underwater
portion of the hull changes.

![](media/image6.png){width="2.180708661417323in"
height="1.4165354330708662in"}![](media/image7.png){width="2.098031496062992in"
height="1.2881889763779528in"}

1.  When the boat rolls to starboard, \"B\" moves to starboard, and when
    the boat rolls to port, \"B\" moves to port.

2.  When the boat\'s hull is made heavier, the drafts increase as the
    boat sits deeper in the water. \"B\" will move up.

3.  When the boat\'s hull is lightened, the drafts decrease as the boat
    sits shallower in the water. \"B\" will move down.

4.  The Center of Buoyancy moves in the same direction as the boat's
    waterline.

**Center of Gravity** (G) is the center of the total weight of the
loaded vessel. It is the point where the entire weight of the boat and
its contents are concentrated. If additional excess weight is added to
the boat then this point "G" will be located higher or lower depending
upon if the weight was added above or below G. The position of \"G\" is
dependent upon the distribution of weights within the boat. As the
distribution of weights is altered, the position of \"G\" will react as
follows:

1.  \"G\" moves towards a weight addition

2.  \"G\" moves away from a weight removal

3.  ![](media/image8.png){width="1.551968503937008in"
    height="1.4909448818897637in"}![](media/image9.png){width="1.7728346456692914in"
    height="1.3838582677165354in"}![](media/image10.png){width="1.8in"
    height="1.4220472440944882in"}\"G\" moves in the same direction as a
    weight shift

When both of these forces, Buoyancy and Gravity are equally oppose to
each other from directly opposite directions then the boat is said to be
"At Rest" or upright.

**Heel** is the temporary tilting of a vessel from side to side. If this
tilt becomes permanent it is then called a List

**List** is a permanent tilting of a vessel to one side or the other.

**Freeboard** is the distance between the water and the working deck of
the vessel. If the deck edge goes under water when the vessel heels, the
danger of capsizing is increased. An overloaded vessel will have too low
a freeboard, and the deck may submerge with even a light heel caused by
wind or water conditions.

**Displacement** is the weight of the volume of water that is displaced
by the underwater portion of the hull is equal to the weight of the
boat. This is known as a boat\'s displacement. The unit of measurement
for displacement is the Long Ton (1 LT = 2240 LBS).

**Force** is a push or pull that tends to produce motion or a change in
motion. Units are expressed in tons, pounds, Newtons, etc. Parallel
forces may be mathematically summed to produce one \"Net Force\"
considered to act through one point.

**Weight** is the force of gravity acting on a body. This force acts
towards the center of the earth. Units are expressed in tons, pounds,
kilograms, etc.

**Moment** is the tendency of a force to produce a rotation about a
pivot point. This works like a torque wrench acting on a bolt. Units are
expressed in foot tons, Newton meters, etc.

**Free surface effect** influences the stability of a vessel. When a
vessel with full tanks heels over, the tank's center of gravity does not
change, so it does not affect the vessel's stability. However, water on
deck, liquids in holds, bilge water, and partially filled tanks will
cause a shift of the liquid with the movement of the boat. When this
happens, the center of gravity also shifts, making the vessel less
stable. This \"free surface effect\" reduces stability and increases the
danger of capsizing.

**Initial stability** is the stability of a boat in the range from 0% to
between 7% and 10% of inclination.

**Overall stability** is a general measure of a boat\'s ability to
resist capsizing in a given condition of loading.

**Dynamic stability** is the work done in heeling a boat to a given
angle of heel.

**Keel (K)** is the base line reference point from which all other
reference point measurements are compared.

![](media/image11.png){width="2.75in"
height="2.203472222222222in"}**Metacenter (M)** is a point where the
lines of buoyant forces intersect as the boat is inclined through small
angles of heel. As the boat is inclined, the center of buoyancy moves in
an arc as it continues to seek the geometric center of the underwater
hull body. The position of the metacenter is a function of the position
of the center of buoyancy, thus it is a function of the displacement of
the boat. The position of \"M\" moves as follows:

1.  As the Center of Buoyancy moves up, the Metacenter moves down.

2.  As the Center of Buoyancy moves down, the Metacenter moves up.

# Stability at Work

![](media/image12.png){width="3.4944444444444445in"
height="1.8430555555555554in"}If an outside force such as a wave caused
this boat to heel over to one side, And if the weight of the boat and
its contents has not changed, or shifted, then the center of gravity (G)
will remain in place. But look at the "B", it moved in the direction of
the lower side. This point is now the center of Buoyancy and the upward
forces of Buoyancy will seem to push harder on this lower side. The
result will be to return the hull to its upright position.

The Metacenter "M" is a point near the centerline of the boat at rest.
It is a point that will normally be stationary and directly over the
point of buoyancy regardless of which side "B" moves. If you consider
"B" as the ball at the bottom of a pendulum then "M" is the connecting
point from which that pendulum swings. The Metacentric Height then is
the distance between the center of gravity "G" and the metacenter "M"
and is simply called "GM".

The GM is crucial to stability. The further apart that "G" and "M"
become, the more stable the boat and the quicker it will right itself. A
long GM also causes an uncomfortable quick snapping roll. To provide a
more comfortable ride, most passenger boats are built with a shorter GM.
This will allow the vessel to slowly recover. Too little GM results in a
vessel with a long, slow roll that, while comfortable, could lead to
capsizing. As long as the weight of a vessel, and the location of that
weight, remains constant, and then the center of gravity would not move.

THE STABILITY TRIANGLE

![](media/image13.png){width="1.75in"
height="1.547244094488189in"}![](media/image14.png){width="1.5in"
height="1.3751968503937009in"}When a boat is inclined, the center of
buoyancy shifts off centerline while the center of gravity remains in
the same location. Since the forces of buoyancy and gravity are equal
and act along parallel lines, but in opposite directions, a rotation is
developed. This is called a couple, two moments acting simultaneously to
produce rotation. This rotation returns the boat to where the forces of
buoyancy and gravity balance out.

The distance between the forces of buoyancy and gravity is known as the
boat's righting arm. As shown above, the righting arm is a perpendicular
line drawn from the center of gravity to the point of intersection on
the force of buoyancy line.

![](media/image15.png){width="1.4375in"
height="0.20833333333333334in"}For small angles of heel (0° through 7°
to 10°, the metacenter doesn't move), the value for the boat's righting
arm (GZ) may be found by using the trigonometry equation of:

With initial stability (0° through 7° to 10°) the metacenter does not
move, and the Sine function is almost linear (a straight line.)
Therefore, the size of the boat's Righting Arm, GZ, is directly
proportional to the size of the boat's Metacentric Height, GM. Thus, GM
is a good measure of the boat's initial stability.

RIGHTING MOMENT (RM)

The Righting Moment is the best measure of a boat\'s overall stability.
It describes the boat\'s true tendency to resist inclination and return
to equilibrium. The Righting Moment is equal to the boat's Righting Arm
multiplied by the boat's displacement.

![](media/image16.png){width="1.3125in" height="0.2604166666666667in"}

As long as the G remains below the M then there will be available
Righting moment to right the vessel. Once G is centered over the M then
the vessel will capsize.

Righting energy is the term used to describe a vessel\'s ability to
right itself after being heeled over. A properly-loaded vessel should
have positive righting energy to a heel of at least 50 degrees. The
magnitude of the largest righting arm is also an indication of a
vessel\'s stability.

# STABILITY CONDITIONS

![](media/image17.png){width="1.5in"
height="1.438976377952756in"}![](media/image18.png){width="1.75in"
height="1.3692913385826773in"}![](media/image19.png){width="1.6251968503937009in"
height="1.5188976377952756in"}The positions of Gravity and the
Metacenter will indicate the initial stability of a boat. Following
damage, the boat will assume one of the following three stability
conditions:

POSITIVE STABILITY

The metacenter is located above the boat's center of gravity. As the
boat is inclined, Righting Arms are created which tend to return the
boat to its original, vertical position.

NEUTRAL STABILITY

The metacenter and the boat's center of gravity are in the same
location. As the boat is inclined, no Righting Arms are created (until M
starts to move below G after the boat is inclined past 7º-10º).

NEGATIVE STABILITY

The boat's center of gravity is located above the metacenter. As the
boat is inclined, negative Righting Arms (called upsetting arms) are
created which tend to capsize the boat.

# Weight Movements

Because of the relationship between weight and buoyancy of a given hull
shape, both GM and righting energy vary significantly with the weight
and center of gravity of the loaded vessel. This means that how a vessel
is loaded has the largest impact on the stability of the vessel.

Adding a load

Adding weight above a boat's center of gravity will change its
stability. If the center of gravity is raised too much, the boat will
become unstable. As a result, less force is required to capsize the
vessel.

Removal of a load

Removal of weight from below the center of gravity also decreases
stability. The center of gravity will rise to a higher level decreasing
the GM of the vessel resulting in a vessel with a quicker roll period.

Shifting a load

Shifting weights vertically, no matter where onboard it is, will always
cause the boat's center of gravity to move in the same direction as the
weight shift. When you raise a weight it will cause a rise in G,
decreasing your stability. This is the reason passenger limits are put
on upper decks of public vessels. The more passenger weight kept on the
main deck the better the stability of the boat.

Shifting weight horizontally, adding a weight off centerline, will
always cause the boat's center of gravity to move in the same direction
as the weight shift. The boat's center of gravity will move off
centerline, the boat will develop a list. A weight shift causing the
boat's center of gravity to move off centerline will always reduce the
stability of the boat.

Whenever weight is added, moved or removed a boat, the boat's center of
gravity rarely moves in only one direction. Fortunately, the effects are
cumulative

# Damage Control

The previous pages have discussed vessel stability characteristics in
the intact state. They also apply to a damaged vessel. However, the
buoyant force and center of buoyancy of the damaged hull will differ
significantly from that of the intact hull, depending on hull
compartmentation as well as the location and extent of damage.

![](media/image20.png){width="2.5416666666666665in" height="2.375in"}

As the unexpected excess weight of flooding water is added, the boat's
center of gravity will initially decrease and the vessel will seem to
become stable. At some point in time the center of gravity will start
rises. Once it reaches the metacenter and goes beyond the boat will
capsize. This new location of the downward force of gravity will now
fight against the righting tendency of the new point of buoyancy that
had shifted previously. The result is that the boat will no longer
return to the upright..

If an area flooded with the water is only partially filled, and there is
no restriction to the side-to-side movement of the water, the result can
be devastating This free movement or sudden shifting of water is called
"Free Surface Effect" and has a major effect on a vessel's stability.

If the area is completely flooded or if there are restricting boundaries
to act as baffles then the water is no longer subject to Free Surface
Effect.

Also, as the boat develops a list, its center of gravity may move in the
same direction as the point of buoyancy if there is also a corresponding
shift in weight as in the diagram.

A good operational practice is to minimize free surface effect by
dividing tanks with baffles and fluid cargo holds with bulkheads and by
keeping the number of partially filled tanks and holds to an absolute
minimum.

# Vessel Stability -- Warning Signs, Precautions

The most important factors in preventing a boat from capsizing are a
well-designed, maintained, and loaded vessel and an experienced operator
and crew. Preventing an unstable vessel condition and being able to
recognize the warning signs when such a condition does occur can save
lives. You should be on constant watch for loss of stability.

-   A well-designed vessel will resist capsizing or foundering in severe
    conditions if it is operated properly. To reduce the likelihood of
    these incidents, keep these rules in mind:

-   Be aware of external forces -- wind, waves, and water depth. Always
    check the weather forecast before departure. Avoid rough weather
    conditions.

-   Don't overload your vessel. Be aware of the amount of weight added
    to your vessel and available freeboard. Distribute the passengers
    and cargo evenly.

-   Partially filled water ballast and fuel tanks contribute to
    instability. Free surface liquids must be contained so their
    influence will not upset the balance of your vessel.

-   Prevent water from entering the interior of your vessel by keeping
    hatches, doors, and windows closed, as practicable, when underway.
    Regular maintenance of gaskets and fastening devices will help to
    ensure water tightness.

-   Any water shipped on board must be removed as quickly as possible.
    Scuppers and drains must meet design criteria and be kept in good
    working order.

-   Adjust course, speed, or both as practicable to minimize vessel
    motion, rolling in particular.

-   Avoid sharp turns or turns at high speed when loss of stability is
    possible.

> Stability Warning Signs

-   Observe the stability and roll of your boat. Make sure the vessel's
    movement and reaction to sea conditions is normal, steady, and safe.

-   Check to make sure your boat is visibly stable before you leave the
    dock. It should not be listing to port or starboard or trimmed
    excessively by the bow or stern.

-   Observe freeboard and check for flooding. A flooded vessel may
    appear stable when it is in fact not.

-   Make sure the passengers remains seated during the voyage.

-   Make sure that bilge level alarms are operational. Unusual operation
    of bilge pumps may indicate an excessive amount of water is entering
    the interior of the vessel.

A combination of prevention efforts and awareness of the warning signs
of instability, along with operator knowledge, can accomplish a great
deal in reducing instability and capsizing.

# The Stability Tests

The USCG has created two simplified stability test that will show the
inherent stability a vessel possesses. The USCG limits the types of
vessels that may use the simplified stability test procedures. The MSU
will shall apply these guidelines to all vessels carrying more than 20
passengers and under 65 feet or those whose stability, in the judgment
of the MSU, require an evaluation.

Simplified Stability Test for Monohull Vessels: The Coast guard
originally developed the simplified stability proof test currently found
in reference (a) in the 1950s. The Coast Guard created this tool to
evaluate the stability of monohull small passenger vessels. The Coast
Guard wrote the regulations in 46 CFR 178.3 10 to apply to certain
monohull small passenger vessels defined as:

-   Less than 65' in length

-   Carrying 150 or less passengers

-   Carrying no more than 12 passengers on an international voyage

-   Having only one hull

-   Having no more than I deck above the bulkhead deck, not including a
    pilothouse, and

-   If a sailing vessel, meets the restrictions in 46 CFR 178.325.

Simplified Stability Test for Pontoon Vessels: The Coast Guard created
the pontoon simplified stability proof test to evaluate the stability of
lightweight pontoon small passenger vessels. The Coast Guard wrote the
regulations in 46 CFR 178.340 to apply to certain pontoon small
passenger vessels defined as:

-   Less than 65' in length

-   Carrying 49 or less passengers

-   Operating only on protected waters

-   Floating on only 2 separate, fully enclosed symmetric pontoons

-   With no machinery or tankage in the pontoons

-   With only one deck accessible to passengers, and the accessible
    portion of the deck does not extend outboard of the pontoons at
    their outermost point, and

-   Constructed with the deck no higher than 6 inches above the top of
    the pontoons.

Other Hull Forms: Since the development of the simplified stability
proof test and the pontoon simplified stability proof test, The USCG has
seen the use of other hull forms for small passenger vessels. These
other hull forms include catamarans, trimarans, and other hybrid
multi-hull types. Catamarans differ from pontoon vessels in that the
hulls often contain machinery, tankage, and piping, the hulls may be
asymmetric, and the hulls are often integral with the deck above. These
vessels shall not perform the monohull simplified stability proof test
or the pontoon simplified stability proof test. These vessels shall
submit stability calculations to the Marine Service Unit for review and
approval.

If the Marine Services Unit questions the stability of the vessel based
on the results of the simplified stability test the vessel owner must
provide calculations to the Marine Services Unit showing the vessel
meets the applicable stability criteria of 46 CFR Subchapter "S" in each
condition of loading and operation.

# Stability Tests

When bring a passenger boat into service on New York State Waters you
must be able to present to the Marine Service Unit stability information
of your boat. Lacking a stability booklet provided by a naval architect,
or a USCG Coast Guard Stability Letter you will have to subject your
vessel to the requirements of 46 CFR Subchapter "S"-Subdivision And
Stability.

To find your boat\'s passenger carrying capacity you will be asked to
perform a simplified stability test or inclining experiment on your
boat. This testing will be performed by a qualified individual of your
choice that has been approved by this office. After changing the
vessel\'s displacement by either addition or removal of weight you may
be require to perform this test again.

If you are required to have a simplified stability test you will either
submit plans of the passenger carrying deck or have a member of the
marine Service Unit measure your vessel. Once measurements are made MSU
will inform you of the maximum person load your vessel can carry. You
must then acquire the services of an approved qualified person to
perform and report the finding of the test.

For the test we will add weight to your vessel, on its centerline,
comparable to the maximum number of person you would carry. This weight
must be raised off the deck to simulate the center of gravity of the
passengers. After the weight has been added a certain amount of weight
is moved to either the port or starboard side, on each deck that you
carry passengers to see how the vessel will react to a large heeling
moment. If half the freeboard does not disappear and the angle of heel
is less than 7 to 14 degrees, the boat ***may*** be certified for the
weight it was inclined at.

In order to facilitate the test you will provide barrels for the water
that will be used as the test weight. Blocks and timbers will be used to
raise the barrels and a high capacity pump to fill the barrels. From the
plans that you submitted MSU will calculate the number of person allowed
to be carried on board. You will have to have one barrel for each 2.6
persons carried, based on a 55 gallon barrel. Concrete blocks and 4x4
timbers will be used to raise these barrels. Plan on having 2 4x4's and
5 concrete blocks for every three barrels that you will use.

Example, 25 passenger boat will need 9.6 barrels so plan on 10 barrels
and 8 4x4's and 20 concrete blocks.

On the day of the test MSU and your qualified person will:

1.  Measure deck areas, aisle, obstructions (bars and non moveable
    items), and measure rail length if there is an outside passage that
    people can stand during the voyage.

2.  Make diagrams of profile of boat and floor plans of each deck and
    mark measurements.

3.  Take fore, aft and midship's freeboard measurements before starting.

4.  Take weight measurements of:

    a.  People that will stay on boat while freeboard reading are taken

    b.  Blocks

    c.  Timbers or planks

5.  Determine where the freeboard reading is to be taken.

6.  Figure shift of weight distance.

7.  Figure weights to be placed on each deck.

8.  Figure movement of weights.

9.  Record number of barrels emptied and number moved.

When the test is concluded the qualified person will complete the
testing procedure forms and forward them to MSU for review. Once MSU has
received and reviewed the paperwork a determination on persons allowed
to be carried on board will be made and the owner will be notified in
writing of this decision.

# Minimum Qualifications for Individuals Employed to Conduct Vessel Stability Testing

(Interested individuals must submit credentials, resume or work history
to the Marine Services Unit for approval prior to undertaking stability
work.)

Naval Architect or Marine Engineer (Credentialed)

Or;

Boat Builder or Manufacturer having 10 of more years experience in
building vessels comparable in size to vessel to be tested as well as
knowledgeable of and experienced in conducting Coast Guard required
stability tests.

Or;

Coast Guard Officer (active or retired) having career experience
(Officer in Charge) in the area of commercial marine inspection (Marine
Safety Office) and having knowledge of and experience in conducting
Coast Guard required stability tests.

**Colleges offering courses in Naval Architecture**

You may want to contact their alumni or placement offices for possible
naval architects.

California Maritime Academy

California State: Long Beach

Florida Atlantic University

Florida Institute of Technology

Maine Maritime Academy

Massachusetts Institute of Technology

Massachusetts Maritime Academy

Memorial University of Newfoundland

SUNY Maritime College

Stevens Institute

Texas A & M University

Texas A & M University at Galveston

U.S. Coast Guard Academy

U.S. Merchant Marine Academy

U.S. Naval Academy

University of British Columbia in Vancouver

University of California-Berkeley

University of Michigan

University of New Orleans

Virginia Polytechnic Institute & State University

Webb Institute

University of Wisconsin

**Professional publications that may have advertise naval architect
services**

Marine Engineer\'s Log www.marinelog.com

Work Boat Magazine www.workboat.com

Professional Boat Builder [www.proboat.com](http://www.proboat.com/)

**Professional organizations that can direct you to a naval architect**

SNAME Society of Naval Architects and Marine Engineers www.sname.org

ASNE American Society of Naval Engineers www.navalengineers.org/

American Boat and Yacht Council [www.abyc.com](http://www.abyc.com/)

**Alternate certifications**

ABYC\'s Westlawn Institute of Marine Technology -- though they do not
grant a college degree, if a graduate can support their work in the
field of ship design and construction with similar sized vessels that
have gone through a USCG certification process and the graduate has
performed several simplified and small boat stability tests that has
been used to issue a USCG stability letter, this office
[may]{.underline} recognize the person's credentials

Professional boat builder, no college degree -- if a boat builder has
designed and built a sufficient number of vessels, of the same or more
capacity as the vessel you have, that have gone through a USCG
certification process and the builder has experience conducting
stability tests, simplified and stability that has been used to issue a
USCG stability letter, this office [may]{.underline} recognize the
builder's credentials

Insert Simplified Stability Test, Mono Hull and Pontoon Here