3d Anaglyph of LVT Alligator Used by the US Marines in World War Two
During World War Two, island assaults required amphibious vehicles that sometimes needed to cross coral reefs on their way to the beaches. The US Marines had a range of specialised amphibious Alligator LVT's (Landing Vehicle Tracked) available, which were developed from a hurricane rescue craft designed by John A. Roebling before the war. LVT's were first used at Guadalcanal in 1942.
The LVT(a)-4 was a version that carried a small howitzer to provide close infantry support during and after the landings. Being tracked meant that LVT's were particularly useful in the Pacific - they were well equipped for crossing coral reefs, other craft had to avoid such obstacles or risk becoming stranded.