GPA - the ugly duckling
The GPA was the amphibious version of the jeep. It was built bij Sparkman and Stevens (who also built the GMC DUKW - Duck - amphibious truck) on a streched GPW chassis. It was standard fitted with a capstan winch and was propellor driven in the water, while steering was done by a little rudder. It's terrain performance however stayed way behind that of a normal jeep and it was slow and unstable in water, thus resulting in a production of only about 12000 units. Nowadays it is a rare and much sought after vehicle. After the war the Sovjets made their own copy of the GPA. Ironically, it's terrain perfomances were much better than the real thing; mainly because it had a higher groundclearance.
The Germans too had an amphibious version of their VW 82 Kubelwagen. This was the VW 166 "Schwimmwagen". Although also a 4 wheel drive, its performances in the water were much better than that of the GPA. Click here for some pics.