LVTs (Landing Vehicle Tracked) were amphibious tractors originally intended to act as cargo carriers for ship-to-shoreoperations during WWII. However, they rapidly evolved into assault troop carriers and fire-support vehicles. These craft were capable of traveling through the water and crossing shallow and sometimes exposed fringing reefs.
Seven LVT models were produced and used in the Pacific, including the LVT(A)-4 that fought in Saipan. This type eventually became known as the “Marianas Model” due to modifications made to the vessel by its crew.
(Text courtesy of Ships of Discovery/Coastal Resources Management/CNMI Division of Historic Preservation/Flinders University Dive Guide)