below deck tank replacement?

[turfman]

I'm looking to replace the tank in my boat to a larger plastic one. Is there some kinda weight ratio formula as to what size or placement in the hull. I'm guessing the larger tank would alter how my boat gets to plane. I don't think the motor on the boat now is the original motor. Present motor is a 115, and 18 gal gas doesn't get me very far.

The boat is an 18ft cc that has an 18gal tank; looking to double that size.

 

[erikgreen]

Re: below deck tank replacement?

One gallon of gas weighs about 6.2 pounds, a bit more or less depending on the exact type.

So figure the difference in getting on plane would be about the same as having a 112 pound person standing where the tank is going to go while getting on plane (assuming you have a full tank of gas at the time).

Where you place that weight will alter your center of gravity some, but depending on where it's at now it might work ok. It's not a significant amount of weight for most boats.

Erik