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Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

1

Canoes, Kayaks, Pontoon Boats and

Inflatables

Capacity and flotation for canoes and kayaks and pontoon

boats are based on displacement. Inflatables though, are

based on interior volume of the air chambers, which easily

converts to displacement.

USA: The Capacity and flotation parts of the Federal

Regulations for recreational boats do not cover canoes and

kayaks, inflatables, and pontoon boats. They are excepted

from these regulations.

ABYC Standards and Technical Information Reports For Small

Craft include all of these. http://www.abycinc.org

H-28 inflatables

H-29 canoes and kayaks

H-35 pontoon boats

In Canada these are covered in TP1332.

http://www.tc.gc.ca/BoatingSafety/regs.htm

Section 4, Hull Design Requirements.

Sub Section 4.3 covers Capacity and flotation for multihull

vessels, that is, pontoon boats.

Sub Section 4.4 covers Capacity and flotation for

inflatable boats.

Canoes and kayaks are not included as long as they are

manually propelled. If they are rated for mechanical

propulsion then the provisions that cover monohull vessels

apply and are found in 4.1.

UK & EU: The RCD applies to all EU states and territories:

Recreational Craft Directive. The RCD is derived from the

ISO standard 12217-3. Stability and Buoyancy for Boats of

hull length less than 6m.

RCD, A.3.2 and A.3.3 Stability and Freeboard and Buoyancy

and Flotation: For boats up to and including 6 metres hull

length.

Canoes and Kayaks are specifically excepted from the RCD.

However if a Canoe is designed to be powered then it is

covered by the RCD as a monohull boat.

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

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See the Royal Yachting Association,

RCD guidelines.

http://www.rya.org.uk/KnowledgeBase/technical/reccraftdir.h

tm.

Australia: National Standard for the Australian Builders

Plate for Recreational Boats, applies to inflatables but

does not apply to canoes and kayaks. It references ABYC

standards, and ISO standards http://www.nmsc.gov.au/#s and

states that the builder must comply with any one of these

standards.

Definitions:

Canoes and Kayaks. The following is the ABYC definition of

canoes and kayaks. The US Coast Guard does not have an

official definition. They use the ABYC definition.

Canoe - A watercraft, designed to be manually propelled, with or without provision for

auxiliary power, with neither end having a transverse dimension greater than 45% of its

maximum beam.

Canoe Length Maximum Beam

14 ft. (4.25m) or less 1/3 Canoe Length

over 14 ft. to 16 ft. (4.9m) 1/4 Canoe Length

over 16 ft. (over 4.9m) 1/5 Canoe Length

Kayak – A watercraft designed to be manually propelled, with or without provision for

auxiliary power with the occupant intended to be seated with legs 90° from the torso.

These boats may have a provision for sealing the opening to the bodies of the occupant or

may be of a sit-on-top style.

Inflatable Boats: A boat that achieves all or part of its

intended structure, shape and buoyancy through the medium

of inflation.

Rigid inflatable boat: (RIB or RHIB) An inflatable boat

with a portion of the hull constructed as a rigid unit and

another portion that all or part of its intended structure,

shape and buoyancy through the medium of inflation.

Pontoon boat: A rigid structure connecting two separate parallel

buoyancy chambers, or pontoons, also often referred to as logs. Each

of the pontoons may have one or more separate sealed chambers.

Although boats with two pontoons are the most common,

sometimes a third pontoon is added for increased capacity.

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

3

Canoes and Kayaks:

Capacity:

The following do not apply to canoes or kayaks designed

specifically for whitewater or inflatable canoes and

kayaks. See the next section for inflatable canoes and

kayaks.

The capacity of a canoe or kayak is determined by first

finding the displacement weight. You can determine

displacement weight by the same method as in lesson 2,

using Simpson’s rule, or by test, by placing weights in the

canoe until water comes aboard. Or alternatively, by

filling the canoe with water and measuring how many gallons

(or liters) it takes.

The maximum capacity is

D = Displacement weight

Wc = Weight of the canoe or kayak.

W =.40 X (displacement weight – weight of the boat)

W = 0.40 (D – Wc)

The weight of the canoe does not include the weight of an

outboard motor if the canoe is rated for mechanical

propulsion. See Appendix A Table I for motor weights

Persons capacity weight equals the maximum weight capacity

or less. If rated for an outboard it equals maximum weight

capacity less the weight of the engine, portable fuel tank

and battery. For boats rated for an engine see Table 1 for

maximum horsepower ratings and weights.

Persons capacity = Persons weight + 32 /141. (rounded to

nearest whole number.)

C ≤ W - (Wm + Wb)

W = Maximum weight capacity

Wm = Dry weight of engine/motor and controls

Wb = Dry weight of battery from Table II (see Appendix A)

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

4

Flotation.

As with other boats the amount of flotation is determined

by finding the amount to float the boat, the people and the

engine, if rated for one.

First find the swamped weight of the canoe or kayak.

Ws = Wc x K

Ws = (___) x (___) = _____ pounds

Ws = Weight of canoe X conversion factor K, for the

material the canoe is made of. See Appendix A Table III For

conversion Factors.

Where: Wc = dry weight of canoe or kayak and K = conversion factor for materials from

Table III

S = Swamped weight of the motor

C = Persons capacity Weight

The amount of flotation needed is:

Wf = Ws + S + 0.1C

If no motor then

Wf = Ws + 0.1C

The cubic feet of flotation is:

F = Wf / B

B = the amount of buoyancy provided by the flotation.

For two pound density foam it is 60.4 in fresh water. (1000

kg/m3)

Flotation material needs to be located symmetrically around

the length of the canoe. If the canoe has a motor then at

least 50% of the flotation for the motor must be in the aft

one third of the canoe (that is the end where the engine

is)

Flotation:Example

A polyethylene canoe weighs 68 lb

The persons Capacity C is 494 lb

Length = 15 feet (4.6 m)

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

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Beam = 35.5” (90.0 cm)

Weight = 68 lb (30.8 kg)

This is a manually propelled canoe and has no provision for an

engine.

The displacement weight is achieved by loading the canoe

D = 1302 (590.6 kg)

W = .40 (D-W) = .40 (1302 – 68) = .40 (1234) = 493.6 (224 Kg)

C = W = 494 lb

Persons = 494 + 32 /141 = 3.7 or 4

Ws = Wc x K (Ws = swamped weight of canoe)

K for Polyethylene from Table III = 0.56

Ws = (___) x (___) = _____ pounds = 68 lb x 0.56 = 38

The amount of flotation needed is:

Wf = Ws + S + 0.1C (for boats with a motor)

If no motor then

Wf = Ws + 0.1C = 38 + 0.1 (494) = 87 lb (43.54 kg)

The cubic feet of flotation is:

F = Wf / B = 96 lb/60.4 lb/cu ft = 1.59 cu ft (39.5 Cu cm)

Inflatable Canoes or Kayaks:

Maximum Weight Capacity – The maximum weight capacity

marked on an inflatable canoe or kayak shall not exceed

three-quarters of the total volume of the main buoyancy

chambers in cubic feet, times 62.4, less the canoe or kayak

weight in pounds

Mwc = .75D-W = Maximum Weight Capacity

D = Displacement = total volume of the air chambers times 62.4.

W = Weight of the canoe or kayak.

ABYC requires that inflatable canoes or kayaks have at least two

chambers if under 12.5 Ft. (3.81m) or three chambers if 12.5 ft

(3.81m) or more.

The Canoe or kayak must be capable of supporting 50% of the maximum

weight capacity with the largest air chamber deflated. So, the

amount of flotation provided by the remaining inflated air chambers

must be at least;

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

6

0.50(Mwc) /62.4 = cubic feet of the

smaller air chamber(s)

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

7

Pontoon Boats:

Capacity:

Capacity for Pontoon Boat is found in ABYC Standard H-35 and in

Canada these are covered in TP1332.

http://www.tc.gc.ca/BoatingSafety/regs.htm

Section 4, Hull Design Requirements.

Sub Section 4.3 covers Capacity and flotation for multihull vessels,

that is, pontoon boats.

There does not appear to be a specific section of the RCD that

covers Pontoon boats.

There are two methods of obtaining the capacity of a pontoon boat.

The first is calculating the submerged displacement and the second

is by adding weights until the pontoons are fully submerged.

To obtain the displacement you need

Total length of the pontoon in feet

Length of the pontoon in inches

Pontoon radius in inches

Pontoon diameter in inches

Boat weight in lb

Engine weight in lb

Most pontoon boats have a nose cone and some have an end cap or cone

on the stern. Do not treat these as part of the length. Only use

the length of the pontoon between the nose cone and the end cap.

Calculate the volume of the nose cone and the end cap separately.

RadiusNose Cone

End Cap

Pontoon Length

The easiest way to determine the volume of the nose cone or end cap

is to fill them with water and measure the amount of water. Another

way is to put them in a tank and add weight until they sink. Either

way can give you the weight of the volume. Then divide the weight

by 62.4 lbs per cubic feet, to get cubic feet.

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

8

For two or three pontoon boats with an

outboard motor and round pontoons:

Volume of the pontoon equals:

The length (inches) x 3.142 X radius X radius. /1728 = vol. cu ft.

Or length cm X r (cm) x r (cm) / 1000 = cubic meters

Volume of the pontoon + volume of the cone + volume end cap. = Total

volume of the pontoon

Do this for each pontoon. If they are all the same size then just

multiply by the number of pontoons. If the boat has a third log

that is a different size then you will have to calculate the

displacement separately.

Add up the volume of the pontoons.

D = Displacement = Total volume of all pontoons X 62.4

Mwc = Maximum weight capacity

Mwc = Displacement – boat weight / Square root of pontoon diameter

in inches minus 2.35 for a two log pontoon

Mwc = Displacement – boat weight / Square root of pontoon diameter

in inches minus 1.35 for a three log pontoon

C = Persons Capacity = Maximum weight capacity – engine weight

Number of persons = persons capacity (weight)/141. = C/141

Example:

Number of pontoons: 2

Pontoon Length (less end cap or nose cone): 252 inches (6.4 m)

Total Pontoon Length: 25.2 feet (7.7 m)

Pontoon Radius: 12.5 inches (31.75 cm)

Pontoon Diameter: 25 inches (63.5 cm)

Nose cone volume 6.5 cu ft

Boat Weight: 2100 lb (952.5 kg)

Engine Weight: 655 lb (297.1 Kg)

(For outboards, use the combined weight in Table 1a Col. 10, in S-

30. For inboard or stern drive use manufacturers weight of engine

and sterndrive package.)

The pontoons on this boat have a nose cone but no end cap.

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

9

The length x 3.142 X radius X radius

/1728 = vol. cu ft

252 X 3.142 X 12.5 X 12.5 / 1728 = 71.6 Cu. Ft.

(640 cm X 3.142 x 31.75 cm x 31.75 cm /1,000,000 = 2.028 cu m)

Volume of the pontoon + volume of the cone + volume end cap. = Total

volume of the pontoon

71.6 + 6.5 + 0 = 78.1 Cu. Ft.

(2.028 + 0.18 + 0 = 2.212 cu m)

Volume of pontoons times 2

78.1 X 2 = 156.2 Cu. Ft. (4.424 cu m)

D = Displacement = 156.2 cu ft X 62.4 lb/cu ft=9746.3 lb(4420.8 kg)

Mwc = Maximum Weight Capacity

Displacement – Boat Weight/ Square root of pontoon diameter – 2.35

Mwc = 9746.3 – 2100 / 5 - 2.35 = 2885.4 lb. (1308.8 kg)

C = Persons Capacity = Maximum Weight Capacity – engine weight

C = 2885.4 – 655 = 2230.4 (1011.7 kg)

Persons = 2230.4 / 141 = 15.8

Determining Pontoon Capacity by Testing.

Maximum Weight Capacity

Add weight to the pontoon boat until all pontoons are awash over

their entire length.

Mwc = Maximum Weight Capacity =

Total Weight – Boat weight/Square root of pontoon diameter - 2.35

(1.35 for three log pontoon boats)

Persons Capacity By Test:

For transverse stability: Place weights for engine, battery and fuel

tank in the location of each item. Add weight on one side of the

pontoon boat evenly distributed fore and aft and as far outboard as

practicable, within one foot from the edge of the platform, until

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

10

the top of the platform on the loaded

side is awash. Repeat this on the other side. Record the weights

for both side.

For longitudinal stability: (fore and aft) Add weights on the

platform, with the center of gravity on the boats centerline. They

shall be placed 1/4 of the length of the deck from the forward end.

Add weight until the forward edge of the deck becomes awash. Repeat

this with the weights placed 1/4 of the length of the deck form the

aft end of the deck. Record the weights.

The smaller of the weights in the transverse stability test or the

longitudinal test shall be used to determine the Maximum Persons

Capacity. The maximum persons capacity is 90% of the weight.

Example

Transverse tests Port = 2500 lbs Starboard = 2550 lb (1020.6 kg)

Longitudinal tests Forward = 2600 lbs Aft = 2650 lb (1202 kg)

The lesser of the above is 2500 lbs. 90% of 2500 = 2250 (1020.6 kg)

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

11

Inflatable Boats

This includes both inflatable boats and rigid hull inflatable boats

(RHIB).

The ABYC standard for Inflatable boats is found in H-28.

Canada has specific standards for capacity of inflatable boats found

in section 4.4 of TP1332

The weight and persons capacity in the following is from the

Canadian standard because it is easier to follow. However, the

results are the same as those determined using the ABYC standard.

Where a power-driven small vessel is of inflatable or rigid

inflatable construction, that is not over 6 m (19 ft 8 in)

in length, the recommended maximum load in kilograms shall

be determined in relation to the total volume of inflatable

tubes (V) and the dry weight of the vessel as follows:

GL = (V X b X 0.75) – W

Where

GL = gross load in kilograms

Vt = the total volume of the inflated tubes in cubic meters,

and where appropriate, the volume of the rigid or inflated

hull below the cockpit sole.

Some inflatable boats have an inflatable chamber in the

floor and this should be included when calculating the

maximum capacities. However I will not include a floor

chamber in the examples and questions.

b = constant buoyancy factor = 1000 kg/m3 (62.4 lb/cu ft)

W = dry weight of the vessel in kilograms

The following variances, dependent on design features, are

applied to the recommended maximum load results calculated

by 4.4.2.1. Load reduction for the minimum number of

chambers in the collar is as follows:

(a) 1 air chamber = 50% load reduction;

(b) 2 air chambers = 33% load reduction;

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

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(c) 3 air chambers = 25% load reduction;

(d) 4 air chambers = No load reduction

C L

Chamber 1

Chamber 2

Chamber

3

Chamber 4Chamber 5

Chamber Volume = Length x radius X radius X pi = L X R X R X 3.1416

5 Chamber Inflatable

If you calculate the volume in inches divide the result by

1728 to get cubic feet.

ABYC defines inflatables by the following categories.

Type I inflatable boat – An inflatable boat capable of

taking a maximum outboard engine power of 4.5 kW (6

hp).

Type II inflatable boat – An inflatable boat with an engine

power rating of greater than 4.5 kW (6 hp) to 15 kW (20

hp).

Type III inflatable boat – An inflatable boat with an

engine power rating of greater than 15 kW (20 hp) to 75 kW

(99.9 hp).

Type IV inflatable boat – An inflatable boat with an engine

power rating of greater than 75 kW (99.9 hp).

Recommended Maximum Number of Persons

Where a power-driven small vessel is of inflatable or rigid

inflatable construction and is not over 6 m (19 ft 8 in) in

length, the recommended maximum number of persons shall be

determined in relation to gross load and engine weight in

kilograms as follows:

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

13

Where

GL = gross load in kilograms

We = engine weight in kilograms (for weight of an outboard

engine use the table in ABYC S-30, col. 3. In TP1332 Table

4-1 it is col. 2)

75 = assumed weight of one person in kilograms (165 lb)

From the ABYC Standard: Persons capacity: The persons capacity

(n) shall be determined by the manufacturer and calculated per H-

28.9.2.1. In no case shall it exceed the maximum load

capacity (m) divided by 75KG (165 pounds).

Do not use the formula Weight + 32 /141 for inflatable

boats.

ABYC Standard H-28 also includes a static stability test

which tests whether the vessel will capsize if a specified

amount of weight is placed on one side or the of the boat.

The test is to be conducted with the engine or equivalent

weight, but without fuel, fuel tank, or battery. The engine

weight shall be table 1a column 3 of S-30.

For ABYC Type 1 inflatable boats the test load in kilograms

is (0.67 X n X 75)

For Type II, III, and IV the test load is (n x 75)

n = maximum number of persons

The test weight is placed to one side of the boat, evenly

distributed along the side, over the inboard side of the

buoyancy chamber.

If the boat capsizes it fails, if not it passes.

Example:

Overall Length: 12.6 Ft (3.8 m)

Inside Length: 8.4 Ft (2.55 m)

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

14

overall width: 6 ft (1.83

m)

Inside Width: 3 ft (0.92 m)

Buoyancy Tube Diam. 1’ 6” (0.455 m)

passengers 6

maximum Weight Cap. 1653 lb (750 kg)

Boat weight 163 lb (74 kg)

Compartments 3

Hp (o/b) 25 hp (19 kw)

Engine weight 187 lb (85 kg)

The boat is given a stability test and the maximum weight

it could support was 450 kg.

Over all tube length = 2 x 3.8 m = 7.6 m (24.93 ft)

V = 7.6 m x 3.1416 x (.455/2)X(.455/2)=1.2358 cu m (43.6 cu

ft)

V = 1.2358 cu m X 1000 kg/cu m = 1235.8 kg (2724.9 lb)

GL = (1.2358 X 1000 X .75) – boat weight(does not include

engine weight)

GL = (1235.8 X .75) – 74 – 85 = 781.35 kg (1722.9 lb)

But Since this is a 3 chamber boat the load is reduced 25%.

GL = 781.35 x .75 = 586 kg (1292.12

Persons = GL – Engine Weight/75 = 586 – 85/75 = 6.68 (7)

However the maximum test weight was 450 kg (992.25 lb)

Persons = 450/75 = 6 persons. (992.25/165) = 6 persons

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

15

Questions:

1. Look at the below boat: is it a canoe using the ABYC

definition of what is a canoe?

Length 15' Beam 38 3/4" Weight 65 pounds Height at Stems 23" Depth 12

a. It is a canoe **** b. No it is not a canoe

Answer: a. The maximum allowable beam for a 15 foot canoe

is 1/4 of 15 feet which is 45 inches. I fits the definition

of a canoe because the maximum beam is less than 1/4 of the

length.

2. A boat is 17 feet long and is 39 inches maximum beam.

The boat has a transom and a mount for an engine. The

transom is 22 inches wide. Is this a canoe?

a. It is a canoe b. It is not a canoe ****

Answer: b. The maximum allowable beam for a 17 foot canoe

is 40 13/16 inches. The maximum allowable width of either

end is 45% of 40.8 which is 18 3/8 inches. The transom

exceeds 45% of the maximum beam of the boat. If the

transom were less than 18 3/8 inches then it would be

less than 45% of the maximum beam and fit the definition

of a canoe.

3. A canoe is made of polyethylene plastic and has the following

dimensions. For K use the value for ABS plastic. The Maximum Weight

Capacity is?

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

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Length = 17 ft 2 in (5.2 m)

Width = 37 in (93.9 cm)

Weight = 80 lbs (36.2 kg)

Displacement = 3265 lb (1480.9 kg)

a. 1306 (592.4 kg)

b. 3185 (1444.7 kg)

c. 1270.4 (576.25 Kg) ***

4. The Maximum Persons Capacity based on Maximum weight capacity

could be.

a. 1302 lb (590.6 kg) or less

b. 1536 lb (696.7 kg) or less

c. 1270 lb (576 kg) or less ***

**** Solution: W = 0.40 (D – Wc) = 0.40 (3265 – 80) = 1270.4 (576.25

Kg)

For the next three questions use the following information:

Number of pontoons: 2

Pontoon Length: 18 feet

Pontoon diameter: 28 inches

Pontoon radius: 14 inches

Boat weight is 940 lb

The engine is a 45 hp outboard

The pontoons are circular.

There are 2 portable fuel tanks of 6 gallons each.

Each nose cone is 4.15 cubic feet.

5. What is the submerged displacement weight for this pontoon boat

a. 5491 lb **** b. 5941 lb c. 2746 lb d. 2647 lb

**** Solution: 18 ft x 12 = 216 inches

Vol = (216 x 3.1416 x 14 x 14)/1728 = 76.97 cu ft

Vol = (76.97 + 4.15) = 81.12 cu ft

D = 2(81.12 cu ft x 62.4 lbs cu ft) = 2(5061.83 lb)=10123.7

6. What is the Maximum Weight Capacity?

a. 2970

b. 2790

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

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c. 2408 ****

e. 2480

***** Solution:

The Maximum weight capacity = Mwc

Mwc = Displacement – boat weight / Square root of pontoon diameter

minus 2.35 for a two log pontoon

Mwc = 5491 – 940 / sq root of 18 – 2.35 = 4551/1.89 = 2407.9 = 2408

Mwc = 10123.7 – 940/ sq rt 28 – 2.35 = 9183.7/(5.29-2.35) =

9183.7/2.94 = 3123.7

7. What is the persons Capacity?

a. 2408

b. 2703

c. 2730

e. 2307

***** Solution: Engine Weight from S-30 table 1a col 10 for a 45 HP

engine = 418 lb

C = Mwc – Engine weight = 2408 - 335 = 2073

3123.7-418 = 2705.7

8. How many persons is this.

a. 12

b. 14

c. 15 ****

d. 17

**** solution: 2073 /141= 14.7 (15) 2704/141 19.1

9. Given the following inflatable Boat

Overall length: 11 ft 6 in (3.5 m)

Inside Length: 7 ft 7 in (2.3 m)

Overall width: 5 ft 3 in (1.60 m)

Inside Width: 2 ft 6 in (0.762 m)

Buoyancy tube Diameter: 1 ft 5 in. (0.4318)

Boat weight 141 lb (64 kg)

Air Chambers 3

Maximum Rated Horsepower 25 (19 kw)

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

18

Engine Weight = 230 lb (119.5 kg)

Chamber 1 and 2 = 8 ft by 1 ft 5 inch diam.

Chamber 3 = 6 ft 1 in by 1 ft 5 inch diam.

End Caps = 0.5 Cu ft each.

C L

Chamber 1

Chamber Volume = Length x radius X radius X pi = L X R X R X 3.1416

Chamber 2

Chamber 3

3 Chamber Inflatable

NOT TO SCALE

8 ft x 1 ft 5 inch

8 ft x 1 ft 5 inch

Diameter

2 ft 6 in

Diameter 5 ft 3 in.

Vol = 9.59 Cu ft

Vol = 12.6 cu ft.

End Caps

Vol = 0.5 Cu ft

What is the maximum Weight Capacity?

*****Solution: 1133 lb (544.5 kg)

Anything with 2 or 3 pounds of this is Ok

GL = V x b X 0.75 - W

Chamber 1 Vol = 138 in x 17in/2 X 17/2 x 3.1416/1728 = 18.097

End Cap vol = 0.5 Cu ft

Total Vol one side = 18.097 cu ft + 0.5 cu ft = 18.597 cu ft

Total volume = 2 x 18.597 = 37.194

GL = (37.194 cu ft x 62.4 x 0.75) – (141) = 1599.6792 lb

For a 3 chamber boat reduce GL by 25%

GL = 1599.6792 x .75 = 1199.7594 lb

Chamber 1 = 3.5 m x .2159 x 0.2159 x 3.1416 cm = 0.512536

End Cap = 0.01416 cu m

Total Vol of on side = .51236 cu m + .0.01416 Cu m = .52652 cu m

Total Vol = 2 X .52652 = 1.05304

GL = (1.05304 cu m x 1000 kg/m sq x 0.75) – (64) = 726.0437kg

For a 3 chamber boat reduce GL by 25%

GL = 702.0201 X .75 = 544.5328 kg

10. What is the maximum number of persons?

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

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Solution:

544.5328 Kg – 119.5 / 75 = 5.667

For English units:

1199.7594 – 230 / 165 = 5.877 = 5.9

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

20

Appendix A.

TABLE I - HORSEPOWER FOR CANOES OR KAYAKS

Canoe Length

Maximum Horsepower Rating

Maximum Kilowatt Rating

Under 15 ft. (4.6m) 3 2.25

15 through 18 ft. (4.6 - 5.5m) 5 3.75

Over 18 ft. (over 5.5m) 7 5.25

TABLE II - WEIGHTS (POUNDS) OF OUTBOARD ENGINE/MOTOR AND

RELATED EQUIPMENT FOR VARIOUS BOAT POWER RATINGS-

HORSEPOWER (KILOWATTS)

Dry Weight-Engine/Motor

Swamped

Weight

Battery

Weight

Submerged

Weight

Engine/

Motor

Horsepower

Rating

kW

Engine/Motor

Portable

Fuel

Tank

Total

Engine/Motor

Engine/Motor

0-2.0† 0-

1.5

30 (13.75 kg) - 30 24 25† 21

2.1-3.9 1.6-

2.9

40 (18.2 kg) - 40 34 29

4.0-7.0 3.0-

5.25

70 (31.75 kg) 25 86 77 51

† and electric motors

Lesson 6 Canoes, Kayaks, Pontoon Boat and Inflatables

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TABLE III - FACTORS FOR CONVERTING VARIOUS CANOE OR KAYAK

MATERIALS FROM DRY TO SUBMERGED WEIGHT

Material

Specific Gravity

Factor

Steel 7.85 0.88

Aluminum 2.73 0.63

Fiberglass 1.50 0.33

Kevlar 1.30 0.24

A.B.S. 1.12 0.11

Oak 0.63 -0.56

Mahogany 0.56 -0.78

Medium Density Polyethylene 0.96 -0.06

Ash 0.56 -0.78

Yellow Pine 0.55 -0.81

Fir Plywood 0.55 -0.81

Mahogany Plywood 0.54 -0.83

Royalex 0.50 -0.95

Cedar 0.33 -1.95

Balsa end grain 0.16 -5.24