I have often wondered why the Marines, with all their hard won experience dealing with amphibious landings, were using tracked landing craft but the Army used the Higgins boat to deliver soldiers to the beach? The invasion planners obviously felt that armored tracked vehicles could operate on Omaha Beach. The invasion plan called for Sherman tanks to be landed and available from the first wave on. https://www.quora.com/Why-werent-tanks-deployed-on-Omaha-beach-during-the-1st-wave-of-D-Day This book asks the same question. D-Day Exposed: A Bad Combat Plan Saved by Good Men, June 6, 1944 Thoughts.