US Military M35 series 2½-ton 6x6 cargo truck being tested underwater in 1951, note extended Air Intake and Exhaust Pipes.

(I found these pictures several years ago but I can’t find the original article anywhere.)
Designed for the US Military by the REO Motor Car Company, the M35 was manufactured from 1950-1999 by;
REO, Kaiser, AM General, Kia & SsangYong (South Korea) and Bombardier (Canada)
Many different variations and models were made and it is still in service around the world.
Original Color & B/W Pictures
LIFE Magazine Archives - Peter Stackpole Photographer