A is for Amphicar, the world's first commercial amphibious car. It wasn't a very good car, and it was a worse boat. Imagine riding in that in two foot waves. There used to be one in the Boston area. It had a vanity license plate which said "GLUG". The license plate was the best thing about it.
I remember back in the 60s, someone took a VW Bug, the old one, not the new one, and drove it across Sydney Harbor in Australia. They were essentially watertight. It had no propellor, and the spinning wheels were what drove it (the turning front wheels steered it. It wasn't a great boat either, but it did float quite well.