Perini (D) contracted to build the foundation of a sewage treatment plant that extends approximately 700 feet over the Hudson River. P, an employee of D, was in charge of all work performed on a cargo barge used to unload caissons and other materials from the supply barges and to set caissons in position for insertion into the embedded rock. Aline used to keep the caissons in position snapped and struck P while he was on the deck of a cargo barge giving directions to the crane operator. P filed a claim under the LHWCA. An Administrative Law Judge determined that P was not 'engaged in maritime employment' under § 2(3) of the Act because his job lacked 'some relationship to navigation and commerce on navigable waters.' P and the Director, Office of Workers' Compensation Programs (Director), appealed to the Benefits Review Board. The Board affirmed on the theory that marine construction workers involved in building facilities not ultimately used in navigation or commerce upon navigable waters are not engaged in 'maritime employment. P appealed. It held that P was not in 'maritime employment' because his employment lacked a ''significant relationship to navigation or commerce on navigable waters.'' The Supreme Court granted review.