I have a Double Eagle 176, and it's time to replace the portable fuel tanks. Previous owner had a 12g and 2-6g tanks sitting under the splash well. Unfortunately it seems like the 12g tank has been discontinued, so hunting for alternatives to maintain or increase my fuel capacity. Area under the splash well is 29" deep x 50" wide and goes from 12" high at the front to 8" tall at inside of transom (middle 20" section is only 6" high at inside of transom). Anybody have any ideas?