Can't find right size boat fuel tank.

[Pete112288]

I just bought a 91 smokercraft alaskan 15ft.
It has 2 compartments in the rear corners of the boat. Inside dimensions 11 1/2 × 30.
I really want a fuel tank that will fit in there rather than have more stuff on the floor of the boat.
I thought I might just get a 3 gallon as I don't do long runs or long says normally. A lot of drifting, anchoring, and electric trolling motor hours.
But wasn't sure. I have been used to a 10hp 4 stroke honda on a lighter smaller boat. Filling a 3 gallon tank last me half the summer.
Now it's a bigger boat and a 1990 25hp Johnson 2 stroke. Figured I should have a 6 gallon tank.
But I can't find one that will fit. It can't be any more than 11 1/2 wide.
Any tips? Really didn't want to have to get 2 separate 3 gallon tanks to make it work.

[Sundance]

Moeller marine website

[metlhead]

Does your Smoker have the step up bow? Just aft of the hatch is a home built steel tank that matches the boat form. Holds 9 gallons and balances great. Any decent SM shop could do it. Tell em it is for water. Made this one after work in less than an hour. Really strong as the step up.

[MADMAX]

I got a smoker craft Alaskan and I run two threes in the back

[Pete112288]

Nope, no step up in front. A small bench seat and flat spot in front of it.

Yeah, I thought about running 2 tanks, 3 gallons each in the back.
Even buying 2 of those is cheaper than the only other option I found so far. Might be what I end up doing.

Thanks guys