What size fuel tank do you have.

[Kender]

This is more for the small boat owners, say 20ish feet or shorter. I am trying to decide how many gallons of fuel to carry on board. Depending on how many gallons the size of the tank, number of tanks, and location of tank can change. I have a small boat and if the fuel amount is above a certain amount the tank sizing will change the seating configuration of my boat. I have a 15ft tri-hull with a 88hp evinrude. I know that each motor is different and what you use it for will change the fuel use. If you could please respond with size/hull config of your boat, engine size, outboard or not, what you use it for, what type of water you operate in (chappy ocean/calm lakes/small wave costal barrier islands/etc.), and how many gallons total do you have. I have the ability, with the right config, to carry a lot of fuel in just 2 tanks but I don't know if I am going overboard (no pun) or not.

I wouldn't normally worry about this so soon but since it impacts my seating arrangement I need to lay out the build.

Thanks
DJ

 

[Challenger84]

Re: What size fuel tank do you have.

11 gallons of fuel
6 gallon tank and a 5 gallon backup in front
16' bowrider w/ 70hp Johnny

 

[Philster]

Re: What size fuel tank do you have.

Had 18-gallon capacity via three tanks on my ol' 18' Chappy with 2-stroker 115 Evinrude.

Rarely used more than 12 (skiing, tubing, cruising all day).

Often, I ditched one for a cooler.

 

[BLU LUNCH]

Re: What size fuel tank do you have.

A single 60 gallon under the console.

 

[superbenk]

Re: What size fuel tank do you have.

Most boats I've seen in the 18-20' range have 25-30 gallon tanks (including mine). More than that & I'd be concerned about weight.

 

[Rscardina]

Re: What size fuel tank do you have.

Most boats I've seen in the 18-20' range have 25-30 gallon tanks (including mine). More than that & I'd be concerned about weight.

Thats not entirely true..Mine is an 20'Aquasport and hold 45 Gallons..My old searay with cuddy only had a 30....My friend had a 20 Grady White that had 80 gallons....go figure..

Superbenk is right about concerns in weight i would check boat spec...i would hate to see you overload or cause other issues....

 

[superbenk]

Re: What size fuel tank do you have.

Thats not entirely true..Mine is an 20'Aquasport and hold 45 Gallons..My old searay with cuddy only had a 30....My friend had a 20 Grady White that had 80 gallons....go figure..

Superbenk is right about concerns in weight i would check boat spec...i would hate to see you overload or cause other issues....

Well, what I said was entirely true, actually... "most boats I've seen in the 18-20' range...". I realize that was a generalization. Seems from what you're saying and what BLU LUNCH with the 60 gallon tank above who appears to have center-consoles that the larger tanks are more prevalent on small boats intended for larger water fishing where you're more interested in length of run time than speed & performance.

 

[JoLin]

Re: What size fuel tank do you have.

Thats not entirely true..Mine is an 20'Aquasport and hold 45 Gallons..My old searay with cuddy only had a 30....My friend had a 20 Grady White that had 80 gallons....go figure..

Superbenk is right about concerns in weight i would check boat spec...i would hate to see you overload or cause other issues....

Different boats, different intended uses.

The Aquasport and Grady are designed for fishing. They can cover a lot of water in a typical fishing day. Grady's get taken offshore a lot, too. They need the capacity and have the hull designs to carry the weight.

The Searay cuddy wouldn't typically be used that way. It might be able to carry the weight okay, but it's built to maximize passenger room. It's a day boat.

Express cruisers like mine usually fall in the middle- we don't typically go real far from home, but might spend a couple days cruising from destination to destination. Mid-20-footers will generally have capacity in the 60-90 gallon range (mine holds 90 and that's way higher than average for a 24').

The OP is talking about a 15-foot tri-hull. It's only suitable for use in fairly calm in-shore or near-shore water anyway, so his fuel requirement is going to be much less. Those running similar boats will have the best take on it.

My .02

 

[ScottinAZ]

Re: What size fuel tank do you have.

18' v-hull bowrider with 115 evinrude outboard
20 gallon built in tank

 

[BLU LUNCH]

Re: What size fuel tank do you have.

Well, what I said was entirely true, actually... "most boats I've seen in the 18-20' range...". I realize that was a generalization. Seems from what you're saying and what BLU LUNCH with the 60 gallon tank above who appears to have center-consoles that the larger tanks are more prevalent on small boats intended for larger water fishing where you're more interested in length of run time than speed & performance.

I forgot also my 1975 Wellcraft V-17 has a 30 gallons under the console.

 

[H20Rat]

Re: What size fuel tank do you have.

16.5 ft, 17.5 ft LOA.
32 gallon tank
Merc 175hp 2 stroke (thirsty little engine!)

1/10th your HP is roughly your max rated gallons per hour. How you use your boat is the sole deciding factor in how much fuel you need though.

 

[marcortez]

Re: What size fuel tank do you have.

An 18 to 20 gallon tank should be plenty for a 15' boat.

That should get you about a 60 mile range....assuming 4 MPG/15 gallons=60.
(3 to 5 gallons as a "get home" reserve)
Your mileage will vary.

 

[Lrider]

Re: What size fuel tank do you have.

My '95 Sailfish 176 CC (17.5 Ft) has a 65 gallon tank amidships

Was designed and built in Florida for the long trips

 

[Rscardina]

Re: What size fuel tank do you have.

Well, what I said was entirely true, actually... "most boats I've seen in the 18-20' range...". I realize that was a generalization. Seems from what you're saying and what BLU LUNCH with the 60 gallon tank above who appears to have center-consoles that the larger tanks are more prevalent on small boats intended for larger water fishing where you're more interested in length of run time than speed & performance.

My bad on the generalization... The point i was trying to make is that not all 18-20 foot boats are built equally. As jolin mentioned, different boats for different strokes... What I was hoping didn't happen was that the OP saw many boats with various capacities and then assume if one boat can handle it that another one must be able to as well.

My friend who i boat with on the rivers here has a 15ft, v hull with a 12 gallon tank, he runs a 70 hp and we usually can go almost all day on that and still have room to spare.

In the end, i would be sure the boat specs allow more feul, if that is what the OP was looking to fond out. If the boats design was a 20 gal tank then I for one would not go exceeding that or i would bring a jerry jug for spare should I need more..

 

[Lrider]

Re: What size fuel tank do you have.

In the end, i would be sure the boat specs allow more fuel, if that is what the OP was looking to fond out. If the boats design was a 20 gal tank then I for one would not go exceeding that or i would bring a jerry jug for spare should I need more..

What I see in boat spec's is they give dry weights both in boat weight and capacity. Although I have a 65 gallon tank, the 1200# capacity, persons, motor and gear does not define the 440 pounds of fuel. However I must assume the fuel is in the motor and gear category. Therefore, 350# for the motor and 440# for the motor leaves me 410# for everything else. (I really need to call Sailfish and ask about that)

On my 16 footer I used to carry three 6 Gal tanks (it had a 40hp) to take me where I wanted to go every day.

 

[Scottimus]

Re: What size fuel tank do you have.

19.5' w/140hp OB
25 gal tank

 

[Rscardina]

Re: What size fuel tank do you have.

What I see in boat spec's is they give dry weights both in boat weight and capacity. Although I have a 65 gallon tank, the 1200# capacity, persons, motor and gear does not define the 440 pounds of fuel. However I must assume the fuel is in the motor and gear category. Therefore, 350# for the motor and 440# for the motor leaves me 410# for everything else. (I really need to call Sailfish and ask about that)

On my 16 footer I used to carry three 6 Gal tanks (it had a 40hp) to take me where I wanted to go every day.

That's a good point. 1 Gallon = 8.35 lbs so, 65 gal = 543 lbs....if your tag says 1200 pound or 6 people...then I assume you throw a guy overboard for evey half tank...

I would think dry weight for the boat (in specs) must factor the weight of the gas or must be calculated (hidden) in there. The boat will need fuel, and a motor + gear is stated on the tag....

 

[PWH1]

Re: What size fuel tank do you have.

16' Glastron open bow.
90 Johnson SPL.
16 Gallon internal tank.

We use our boat on inland lakes for skiing, tubing and some fishing.

 

[Lrider]

Re: What size fuel tank do you have.

Actually water weighs 8.35 pounds per gallon, gasoline weighs in at about 6.25 pounds per gallon, that is why it floats on water. Could be a little more for 2-cycle gas

Be well

 

[Rscardina]

Re: What size fuel tank do you have.

I was never good at weights and measures...and I am not smarter than a fifth grader....