I've been using it for a couple of days without any problems. Made a re-suply rendezvous with the supply ship 'Bessel' near Vigo, Spanish coast - got my tank topped up and new torps - and went straight back out, up to the irish sea, where I bagged a few more merchants - great fun.
The 'Bessel' is a good, sturdy-looking crate, BTW.
Screenshot to follow (if I can remember my Photobucket password :P )
Hawkers
