Groco

About Groco: A Century of Marine Innovation

Few names in the marine hardware industry carry the weight of experience and craftsmanship that Groco does. Short for Gross Mechanical Laboratories, Inc., Groco was founded in 1918 by Angus Roy Gross Sr. — a tinkerer and innovator who started the company in the basement of a Baltimore row house. From those humble beginnings, Angus and his personally trained team built a reputation rooted in precision engineering and an uncompromising commitment to quality that continues to define the brand more than a century later.

Headquartered in Stevensville, Maryland, Groco has long been the go-to source for boaters and marine professionals who demand components that perform reliably in the demanding saltwater environment. Angus's inventive spirit led to numerous patents across a surprisingly diverse range of products — from carbonating faucets to automotive tail lights — but it was marine hardware where Groco truly found its calling. That same drive to improve and redesign is baked into every product Groco produces today.

What Groco Makes

Groco's catalog spans a wide range of below-the-waterline and through-hull marine hardware, with two standout categories that have earned particular loyalty among boat owners and shipbuilders alike.

One of Groco's most trusted product lines is their sea strainers. Designed to protect raw water cooling systems, pumps, and engines from debris and fouling, Groco sea strainers are engineered to handle the rigors of continuous marine use. Whether you're outfitting a small inboard cruiser or a large commercial vessel, the right strainer is an essential safeguard — and Groco's lineup offers solutions across a wide range of flow rates and installation configurations.

Equally important to any vessel's integrity are reliable thru-hull fittings. These critical components form the sealed connections between a boat's hull and its plumbing systems, and a failure here can have serious consequences. Groco's thru-hull fittings are manufactured to exacting tolerances, using materials suited for long-term exposure to seawater. Boaters and marine builders have trusted Groco's fittings for generations precisely because the stakes are too high to compromise.

Why Boaters Choose Groco

• Over 100 years of marine expertise — founded in 1918, with deep roots in innovative engineering
• Made in the USA — headquartered in Stevensville, Maryland, with a tradition of American craftsmanship
• Engineered for longevity — products are built to withstand the corrosive, high-stress marine environment
• Broad product range — with nearly 400 products across multiple marine hardware categories
• Trusted by professionals — used by boat builders, marine mechanics, and serious boaters worldwide

Whether you're replacing aging hardware on a classic cruiser or speccing out a new build, Groco's marine hardware represents a standard that serious mariners have relied on for over a century.