I've read a little about them. The butt was blocked in. No one could handle that kind of recoil. The gun was blocked in and they aimed by steering the boat with those little hand paddles. More than 1 of them got knocked out of the boat and boats were known to sink after the recoil tore it apart.

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.