for the Seabees rebuilding the airstrip and aid in the burial detail. The 2nd Marine Division remained in Hawaii for six months, refitting and training, until called upon for its next major amphibious landing, the Battle of Saipan in the Marianas in June 1944. Lessons The greater significance of the action on Tarawa to the success in the Marshalls proved to be the lessons learned from the battle itself. It was the first time in the war that a United States amphibious landing was opposed by well entrenched, determined defenders. Previous landings, such as the landing at Guadalcanal, had been unexpected and met with little or no initial resistance. At the time, Tarawa was the most heavily defended atoll invaded by Allied forces in the Pacific. The losses by the United States at Tarawa resulted from several contributing factors, among which were the miscalculation of the tide and the height of the obstructing coral reefs, the operational shortcomings of the landing craft available, the inability of the naval bombardment to weaken the defenses of a well entrenched enemy, and the difficulties of coordinating and communicating between the different military branches involved. Navy battleships and cruisers had fired some three thousand shells into Tarawa in the three hours before the landings. "This was by far the heaviest bombardment of an invasion beach ever delivered up to that time. Yet it proved inadequate. ... The high explosive shells employed by the bombarding ships usually went off before penetrating the Japanese defensive works (thus) doing little real damage." For the subsequent Marshalls campaign, the naval bombardments took a month and included the use of armor-piercing shells, while the landing craft also had armor. The failures of the Tarawa landing were a major factor in the founding of the Underwater Demolition Teams (UDT) the precursor of the current U.S. Navy SEALS – after Tarawa "the need for the UDT in the South Pacific became glaringly clear". The "landing on Tarawa Atoll emphasized the need for hydrographic reconnaissance and underwater demolition of obstacles prior to any amphibious landing". "After the Tarawa landing, Rear Admiral Richmond K. Turner directed the formation of nine Underwater Demolition Teams. Thirty officers and 150 enlisted men were moved to the Waimānalo Amphibious Training Base to form the nucleus of a demolition training program. This group became Underwater Demolition Teams (UDT) ONE and TWO." Legacy War Correspondent Robert Sherrod wrote: Over