Groco (Gross Mechanical Laboratories)

GROCO: Over a Century of Marine Hardware Excellence

When it comes to dependable marine plumbing hardware, few names carry the weight of GROCO — short for Gross Mechanical Laboratories, Inc. GROCO was born in the basement of a Baltimore row house around 1918, founded by Angus Roy Gross, Sr. on the twin pillars of innovative design and sound construction. Over a century later, the company remains a benchmark for quality in the marine industry, still family-rooted and still engineering solutions that outperform the competition.

GROCO's path into the marine world was shaped as much by passion as by engineering. Founder Angus Gross developed deep ties to the boating community, co-founding the Corinthian Yacht Club on Maryland's Chesapeake Bay and forging a friendship with legendary yacht builder John Trumpy. Through decades of hands-on tinkering aboard more than 30 boats and yachts, the Gross family refined existing marine components and invented new ones — a tradition of continuous improvement that has never stopped.

Even during World War II, GROCO answered the call: at the direction of the U.S. War Department, the company designed and produced tank engine oil coolers and water strainers for beach landing craft — patented products that remain in production to this day. That legacy of durability under extreme conditions speaks directly to the quality boaters can expect from every GROCO product.

What GROCO Makes

GROCO specializes in a broad range of marine hardware, including valves, seacocks, fittings, pumps, marine toilets, water pressure systems, heat exchangers, and — most notably — raw water strainers. Their product lineup spans both recreational and commercial vessel applications, with solutions engineered for corrosion resistance and long-term reliability in demanding saltwater environments.

At the heart of the GROCO catalog are their renowned sea strainers. Recognized across the marine industry as a standard of quality for raw water filtration, GROCO strainers are constructed from heavy bronze and stainless steel and are available in a wide range of port sizes to suit engines, air conditioning units, generators, and more. From compact basket strainers to high-flow models for large commercial engines, GROCO offers a solution for virtually every raw water intake application.

GROCO also leads in innovation with their HYDROMATIC self-cleaning strainer technology, which performs periodic automated cleaning cycles to prevent filter basket clogging — eliminating unscheduled shutdowns and reducing maintenance demands. Their SSA Raw Water Monitoring System adds another layer of protection, alerting vessel operators to significant reductions in raw water flow before damage can occur.

Why Boaters Trust GROCO

With more than a hundred years of marine manufacturing behind them, GROCO has earned the trust of professional mariners, yacht builders, and weekend boaters alike. Their products are UL Listed, built to ABS and USCG compliance standards where applicable, and engineered to perform in the harshest marine environments. Whether you're fitting out a new vessel or replacing a worn component, GROCO delivers the quality and peace of mind that experienced mariners demand.