To allow U.S. military vehicles to drive through deep water during World War II beach landings, the armed forces devised a fascinating method of waterproofing involving a goopy putty called “Asbestos Waterproofing Compound.” Here’s a video showing all the steps needed to keep that Jeep moving through the deep stuff.

Water and internal combustion engines just don’t go together, we’ve shown that and and again. But during World War II, particularly in Europe, allied forces needed to conduct beach landings, wherein soldiers and vehicles were dropped from landing crafts, often far from the shore.

To withstand these beach landings, military vehicles had to be thoroughly waterproofed. The air intake and gasoline vent had to be extended, and pretty much every electronic connector and button had to be covered in what the U.S. military called AWC for Asbestos Waterproofing Compound.

The military’s waterproofing kit contained not just the big AWC patty, but also wire, friction tape and rubber impregnated tubing. When done properly, the U.S. Army Signal Corps claimed, the sealing job could keep a Jeep running for up to six minutes in depths of up to 3.5 feet of water.

That’s a full foot higher than the water fording rating on the new Jeep Wrangler, and means the little Jeep can drive with water filling the entire cabin all the way up to the base of the windshield.

Those little Willys MBs are beasts.