The supporting naval bombardment lifted .
The Marines started their attack from the lagoon at 0900 , thirty minutes later than expected , but found the tide had not risen enough to allow their shallow draft Higgins boats to clear the reef .
The supporting naval bombardment lifted and the Marines started their attack from the lagoon at 0900 , thirty minutes later than expected , but found the tide had not risen enough to allow their shallow draft Higgins boats to clear the reef .