U.S. naval personnel were among the first ashore at Normandy. Most notably, Naval Combat Demolition Units cleared gaps through the beach obstacles so that reinforcements and logistics could quickly come forward. A Gap Assault Team consisted of an officer, 13 combat demolition trained sailors, and 26 soldiers for security and support. Sixteen such teams came ashore on Omaha Beach at 6:33 a.m., and a similar number on Utah Beach at 6:35 a.m., within minutes of the first troops ashore. Obstacles were initially blown with Hagensen C2 Packs, each holding two pounds of explosives. A team member typically carried 20 such charges.
On Omaha Beach the Naval Combat Demolition Units suffered 41 percent casualties, but successfully blew eight 50-meter wide lanes initially and saw the beach fully opened by D-Day plus 2. On Utah Beach resistance was less intense, and the teams cleared a frontage of 700 yards within the first two hours with few casualties. As the landings progressed more and more naval personnel arrived, including fire support parties, communications teams, engineers, beach liaison parties, debarkation control teams, and others.