Fuel Tank Size Scott Brear 2/1/1999 Hull #: 31 I spoke with Jerry Douglas about this long suffering problem. According to Jerry, all tanks up to boat 177 were 27.5 gallons as determined by outside measurement allowing for wall thickness, etc. Boat 178 will have a 34.3 gallon tank. The new tank can be retrofitted via a drop in; ie, no fiberglass work. It costs $322.35 FOB factory.