and re-inflate to rendezvous with the awaiting submarine at a predestined point. As for the Marine assault teams they found that getting their equipment to the beachhead during an amphibious landing was a strenuous task and extremely difficult with the existing landing craft. Most of the landing boats were incapable in hauling amphibious tractors, artillery and other important supplies necessary for properly establishing an advanced base. The Marines requested the Bureau of Construction and Repair to design and build feasible landing craft, but to no avail. Soon the Marines began to express interest in a variety of different commercially produced boats. Of all these tested, the Higgins' boats became the best choice. When tested during FLEX 5 by the Navy and Marine Corps, Higgins' Eureka boat surpassed the performance of the Navy-design. A drawback to the design was that equipment had to be unloaded, and men disembarked, over the bow or sides, thus exposing them more to enemy fire in combat situations. The Marine Corps requested that the boats have retractable hinged ramps at the bow-replacing the machine gun mounts; and it was adopted as the standard personnel landing craft, the Landing Craft Personnel (LCP(L)) by 1940. FLEX 6 Fleet Landing Exercise Number Six was the first wartime exercise in amphibious training in 1940–1941. It became clear that the Navy and Marine Corps was in dire need for amphibious transports larger than destroyers as the 1st Brigade could barely send two thousand Marines to land in the Caribbean and only adequate experimental landing craft were provided. Landing craft included two tank lighters, two artillery lighters, twenty-five special landing craft, of which twelve were the Bureau type, and eight landing skiffs. Comparative tests showed the Higgins Eureka landing craft, the 45-foot tank lighters, and rubber boats to have been the best adapted to landing operations. As a partial response to this problem, H.M. Smith seized the newly developed destroyer-transport. During FLEX 6, his plan called for the to land Company A, 1st Battalion, 5th Marines via rubber boats during the night, at H-minus three hours, at a point away from the primary assault beach. This force would advance inland, seize key terrain dominating the proposed beachhead, and thus protect the main landing from counter-attack. They were the first unit to use the revamped Manley. On 23 February 1940 it used rubber boats to execute an assault landing against Culebra. In 1940,