Here is a very interesting Willys-Overland press
release published in the Oxnard Press-Courier on May 15, 1950.
Willys-Overland Makes First Shipment of Underwater Jeeps for Navy
Toledo, Ohio - First shipments of 1,000 underwater Jeeps for use by the
Bureau of Ships, Department of the Navy, are being made by
Willys-Overland the company announces. The 1,000 vehicle Navy contract
calls for radios and parts, and aggregates more than $3 million, and is
expected to be completed by the end of the May, the company said. The
underwater Jeeps have the same outward appearance as the civilian
Jeeps. Principal differences are in engineering features under the body
and hood. The Navy Jeeps are equipped with deep water fording equipment
which enables them to operate completely submerged. Before delivery, a
sampling of each day's production is given a rigorous underwater test.
Officials require that the Jeep operate for 15 minutes under water. One
phase of the test is the starting and stopping of the engine while the
vehicle is completely under water. Each vehicle likewise is given an
air pressure test to assure a complete crankcase seal. The testing
procedure includes a check of radio suppression and conduction as well
as road trials. All vehicles have two-way radio equipment.