The B361 stretches 9 gallons along a 25.5 x 10.5 x 8.5 inch molding - a longer, narrower take on the small-tank problem than its shoebox siblings. The extra length is the useful part: it rides flat along a frame rail, a cockpit side, or the back edge of a storage bay, keeping its 10.5-inch width out of the way of everything else you need to fit. Same gallons, different geometry; that is the B-series catalog working as intended.
Dual-role by design: order fresh water fittings and the FDA-compliant polyethylene serves potable duty; order waste fittings and the identical blank becomes a low, narrow gray or black holding tank. On a molding this proportioned the outlet position matters - put it at the low end of your actual installed tilt, which is exactly why Ronco installs fittings to your marks rather than to a template. Print the drawing below, work the on-page fitting planner, and the ports are spin-welded or thread-installed in Tustin, California, home of this build-to-order craft since 1974.
It ships at 14 lb and carries about 75 lb full, so restraint is not optional. If the shape is close but the numbers are not, the small end of the boat tank category and the van-friendly range in RV water tanks hold the alternatives, with waste-first shapes in RV holding tanks and everything Ronco molds on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B361 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.
