The BOAT38W runs 36 gallons down a 45 x 18.5 x 11.25 inch corridor - almost 4 feet of tank shaped to live along a settee base, a berth flat, or the outboard shelf of an engine space. Long, moderate-width, under a foot tall: these are the proportions that let a cruising boat carry real water without surrendering a locker you would miss.
Ronco molds it to the H.D. marine spec, with a wall meaningfully thicker than the light-duty RV shells, in FDA-compliant polyethylene rated for drinking water. Production is Tustin, California, as it has been since 1974. Fittings are installed per order - spin-welded or threaded wherever you mark them - so print the drawing below and use the fitting planner on this page to lay out fill, vent, and pickup before you buy.
Full weight is about 300 lb, distributed along the full length, so support the bottom continuously and strap it against lift. See other long-format tanks in boat tanks, price the shipment on the freight cost estimator, or survey the range at the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.