Since it's just a bowfishing boat I might use a power sander. You'll have to use a primer, but once again, since it's a bowfishing boat, you won't need to use an etching primer, just regular primer. I suppose if you didn't care how it looked you could do it hillbilly style with a roller!
Since it is just a fishing boat I would just use the power sander to knock off the loose finish and spray primer over that. Then you could paint it whatever color you wanted. I never have bothered to paint any of my old aluminum boats. You could get a spray on liner for the interior like they put in pickup beds and that will help knock down the noise and give you a non slip surface that will hold up really well. Have fun with your boat.