Now on to the actual production model M38. The average M38 came with an L-134ci 4 cylinder engine, with a single bore Carter downdraft carb, a spicer T-90 3 speed cane transmission, the model 18 transfer case, 16" rims allowing for the 7.00-16's on all four corners. Some M38's had the combat rims which facilitated thechanging of tires by falling into 3 different pieces, some had the winter kit whichincluding such items as a full or half cab made of aluminum (and the full cab willsupport the weight of 3 people) a water type heater (takes heat from engine) or a gaspowered heater (killed your mileage ~17mpg to 9 or 10 mpg when running) a heater core for the engine, and a heater core for the batteries, some had a full submersion ability of 72" or 6' underwater when equipped with the air and exhaust snorkel (they were knownto be able to start underwater as long as the system remained pressurized and all ports (including clutch drain) were sealed). The rare few had a PTO winches, for the '52's thatwould be 1 in 100 got them, and some may have had other PTO operated equipment. There some arguments have occurred about what was the original manufacturer of winch used but in fact, many were used, but only the ramsey model 50(?) is demonstrated in the manuals and is rated for either 1 ton or 4 ton, depending on the model. The M38A1 came with the 4 ton model if so equipped.

They even had one driver/diver change a tire underwater

1000 modified CJ-3A's were produced for the U.S. Navy as the underwater
CJ-V35/U

This line right here tells me you shouldn't be in the mud. If you cannot pull into the mud, stop, then get yourself out, why bother? Snorkels were designed for fording streams and rivers, something that is done at a low rate of speed.