In the book, The Luftwaffe in the Battle of Briton by Van Ishoven, their is a section on these odd duck's. Aparently they mored them out in the chanel and the idea was for German airmen who had to ditch to seek out the closest one and set down near it, they had bunches of them set in different places so the idea was you dident half to look very far to find one.
Once inside their were bunks, heat and chow and watter, and a radio, and some first aide stuff.
Aparently they had the habait of breaking lose and floating off, and I dont think they were in active service for very long.
The Brits called them Lobster pot's.
