I am happy to say that the Boston Duck Tour people are not worried. I have been on a couple of their tours.

An amusement not provided by such tourist services is that you can go surfing in them. Climb up the back of a breaking wave, hook your front wheels over the top, and ride it in. It deposits you on the beach, and you can drive on up. There is a chapter in Bascom's _Waves and Beaches_ in which he describes doing that, for research purposes, in northern California surf (30-ft waves). Not a dull page in it.

Tho they were developed for military use, their utility for rescue was recognized from the beginning. They must have saved a lot of lives.