Tracked Boat from WWII

From the Germans during WWII: Panzerfahre Gepanzerte Landwasserschleppen. This tracked boat claimed to carry 20 people plus 3 operators. It was the early development efforts for a more effective amphibious landing craft capable of traversing difficult terrain and able to make significant inland maneuvers. Capable of sea launches to transport onto land as well as cross rivers and other water barriers to land access.

Second iteration opf the concept -- the Panzerfahre Gepanzerte Landwasserschleppen 2 -- more closely resembles modern landing craft. This example has startling similarity to the modern US efforts as described here.