Somewhere between the day-boat sizes and the cruising sizes sits 21 gallons, and the Ronco Plastics B148 owns that slot at a 28 lb ship weight. It is a marine fresh water molding in FDA-compliant polyethylene - a one-piece shell with no welds, no seams, and no galvanic drama, which is why polyethylene replaced metal in this job decades ago. Ronco has been part of that shift since 1974, molding in Tustin, California the whole time.
The B148 ships without pre-cut ports because Ronco installs fittings per order: spin-welded or threaded, at your marked locations and sizes. Treat the drawing below as your planning sheet - print it, position the fill where your deck plate drops, the vent where air can escape uphill, the pickup where the tank drains driest - then commit the layout in the fitting planner on this page.
Full, the tank holds about 175 lb of water; at 8.34 lb per gallon even modest tanks become structure-relevant, so give it a flat, supported base and real hold-downs. Neighboring capacities are under boat tanks, and the complete family - water, waste, marine, RV - is on the Ronco Plastics hub. Shipping to your ZIP is a two-click check at the freight estimator. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B148 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.
