Thirteen gallons is a tank for the boat you actually own, not the boat in the brochure. Small cruisers and pocket powerboats have water systems measured in sinks, not showers, and the B218 feeds one properly: enough fresh supply for a weekend of dishes and hand-washing, in a marine molding shaped to disappear into the odd leftover volumes small hulls offer.
The shell is rotomolded FDA-compliant polyethylene - potable-rated, one piece, no seams. It ships at 74 lb without fittings, because Ronco installs those to order: print the drawing below, mark your fill, vent, and pickup where they clear the hardware already crowding a small boat's lockers, and the shop spin-welds or thread-installs each one to your marks. The on-page fitting planner records the same layout with clicks.
Full, the tank holds about 108 lb of water at 8.34 lb per gallon. That is modest, but it is still weight that moves - so bear it flat, strap it down, and place it where the trim can carry it. Ronco has molded small-craft tanks alongside its big ones in Tustin, California since 1974; capacity never decided who got the good engineering.
See what else fits a small hull in the boat tank category, or scan every molding on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B218 dimensional drawing - print it to plan your install and mark exactly where you want fittings located; Ronco installs spin-weld or threaded fittings to your marked spec.
