new guy looking for ideas

[3cells]

Hi all,
Looking for some info from you experienced mini-types, that have managed to survive the experiences!
I’m a saltwater fish-o-maniac, living on the forgotten coast of FL (NW, not panhandle) I have a fiberglass double hull jon boat that I salvaged from the dump, 15.5 X 48 where it counts, 16” gunnels,it weighs a ton… well, more like 500 Lbs +.
I needed a motor to replace an old 5.5 HP Evinrude. A friend gave me a 35 HP Rockwell JLO airboat motor, circa 1969-ish from his duckboat, the price was right (I’m a homesteader on fixed income, SSI), so a couple months and some fiberglass and metal fabwork later, (I made a venturi cowl for the prop, it seems to help a bit). I put it in the water and started chasing the reds and trout. I absolutely love this crazy thing, but I only get about 6-7 MPH, It plows. The setup I have is great, casting deck up front, nice spacious flat interior, really stable in the water, but I fish the gulf, weather permitting. I range 1-3 miles out, when I’m doing the flats, and inshore creeks. I’d like to venture as far as 8 – 10 miles out, for the reefs and wrecks, but if a blow comes up, you really need to get off the water quick as you can.
I know jon boats are not the ideal hull, but I can’t afford the materials to build one from scratch, much as I’d like to.
So, what if I use an old 14’ aluminum jon boat, split it down the middle, add 1’ to bring it to 5’ between the chines, & rework the bottom with 1/8”, to get that smooth plane surface? I can dig up a couple hundred for 1/8” sheet, & some structural channel, & can scrounge up a redneck tig setup for my old Forney stick welder. I’m not building a racer, but do you think I could get maybe 10-15MPH out of a hull like this, with this JLO direct drive pushing some unknown brand 42” wood/stainless prop? Average payload would be me and wife + gear, maybe 300Lbs (we’re small folks) I don’t have grand aspirations of planing, would be great if it could, but I understand the physics are against me. I probably will try the jon boat as is, first, but…

If I were able to afford the materials, I’d probably go for about 13.5 X 70’’ with 25” gunnels, (for 1-3’wave height) with flotation styro in every conceivable nook and cranny. Any helpful input is welcome, and yes, I know I’m crazy, can’t help it!