GROCO (Gross Mechanical Laboratories, Inc.) was born in the basement of a Baltimore row house in (approximately) 1918, with a pair of workers trained personally by founder Angus Roy Gross, Sr.  This was a time when the entrepreneurial spirit flourished in America and when the industrial boom stood on the shoulders of an expanding steel industry and quickly growing automotive and marine industries. 

Most founders of marine industry companies were here because of a love of the water and a passion for boating, and Angus was no exception.  An avid boater, he raced early versions of hydroplanes in the 1920's and briefly held the speed record for one class of boats in 1926 while piloting the Lady Baltimore off the coast of Palm Beach, Florida.  In 1929 Angus founded the Corinthian Yacht Club in Maryland's Chesapeake Bay.