Botterjacht

Is it historically correct or not Proulx just do that?

It seems that it's just a story Cuzzi link to a script. And I could not find anything more than that.

But I have met SeaLion Operation

In fact, a botteryacht was constructed during the war in the Netherlands, ordered by an officer of the German army. The yacht was completed after the war and has a very interesting story. The story can be downloaded here:
http://www.cometosea.net/albums/cometosea/GrooteBeer.htm Flag

Consisting of course. The Fa¼hrer could not swim and hated water. He would not even ride in a boat in Berchtesgaden.

s_e_a