The supporting naval bombardment lifted and the Marines started their attack from the lagoon at 09:00, thirty minutes later than expected, but found the tide had not risen enough to allow their shallow draft Higgins boats to clear the reef. Only the tracked LVT "Alligators" were able to get across. With the pause in the naval bombardment, those Japanese who had survived the shelling were again able to man their firing pits. Japanese troops from the southern beaches were shifted up to the northern beaches. As the LVTs made their way over the reef and into the shallows, the number of Japanese troops in the firing pits slowly began to increase, and the volume of combined arms fire the LVTs faced gradually intensified. The LVTs had a myriad of holes punched through their non-armored hulls, and many were knocked out of the battle. Those 'Alligators' that did make it in proved unable to clear the sea wall, leaving the men in the first assault waves pinned down against the log wall along the beach. A number of 'Alligators' went back out to the reef in an attempt to carry in the men who were stuck there, but most of these LVTs were too badly holed to remain seaworthy, leaving the Marines stuck on the reef some off shore. Half of the LVTs were knocked out of action by the end of the first day.