Most tank replacements fail at the tape measure. The original went in before the deck did, and the hatch it has to pass through today is smaller than the tank is. This is where a catalog like Ronco's earns its keep: the B191 is one of dozens of 30 gallon marine water tank shapes the shop molds, each drawn around a different hull cavity, so the odds are good that one of them threads the needle between your stringers. Study the drawing below against your space before you commit.
The tank is rotomolded FDA-compliant polyethylene for fresh water service - a one-piece shell with no welded seams, which matters in a hull that flexes. It ships without fittings on purpose. Your old tank's plumbing dictates where the fill, vent, and pickup should sit; print the drawing, mark those points, and Ronco installs each fitting to your marks, spin-welded or threaded. The on-page fitting planner does the same job with clicks instead of a pen.
At 36 lb the bare tank is a one-person carry, and full it holds about 250 lb of water at 8.34 lb per gallon - so reuse or rebuild the original bearers rather than trusting a pair of straps alone. Ronco has molded marine tankage in Tustin, California since 1974, long enough that the shape you are replacing may well have come out of the same building.
Browse alternate 30 gallon footprints in the boat tank category, or see everything the shop makes on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B191 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.
