At 29.75 x 13.88 x 8.12 inches, the BOAT3W is a plank of a tank: 12 gallons of fresh water in a shell barely more than 8 inches tall. That profile is made for the spaces boats actually have - under a cockpit sole, beneath a V-berth step, flat against the turn of a small hull - where capacity has to come from length and width because height is simply not on offer.
It is a heavy-duty molding despite weighing only 9 lb as a blank, with the thicker marine wall in FDA-compliant potable polyethylene. Full, it carries about 100 lb of water spread thin across the footprint, an easy load for any reasonably supported flat.
Fittings are installed per order at Ronco's Tustin, California plant - spin-welded or threaded to your marks, the house method since 1974. On a tank this shallow every fitting competes for the same top surface, so print the drawing below, lay out fill, vent, and pickup deliberately, and finalize in the on-page fitting planner.
More small marine shapes are under boat tanks; the closest land-side sizes live in RV water tanks, and the whole catalog is on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.