From 1914 to 1917 there were a couple of amphibious vehicles called Hydromotor. They were built first in LA, later by the Automobile Boat Manufacturing Company Inc. in Seattle.
I don´t believe any of them has survived. However I remember in one of the past IAOC newsletters there was a very small copy of a Hydromotor stock paper. I would be very pleased to find one of those papers or even a nice scan of the original stock.

Can anybody help?