The BOAT57W is a 20-gallon block in the most conventional proportions on this page - 32 x 16.5 x 10 inches, roughly two-to-one in plan and low enough to disappear under a berth or bench. When a boat's designer left one honest rectangular void and you want it full of drinking water, this is the shape that claims it without drama.
It is molded to Ronco's H.D. marine spec, with a wall built heavier than the light-duty series, in FDA-compliant polyethylene rated for potable supply. Tustin, California, since 1974. Fittings go in per order - spin-welded or threaded at the marks you set - so print the drawing below and place your fill, vent, and pickup with the fitting planner on this page.
Full, it carries about 167 lb, an easy load for a supported shelf with a strap over the top. Compare 20-gallon-class options in boat tanks, or see everything Ronco molds on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.