U-Boat #'s
 

I've noticed a lot of you have a U-Boat # attached to your signature or avatar. Why did you choose that particular U-Boat ?

For myself, I use U-31 because, as far as I know, it's the only U-Boat to be sank twice. It was sunk with all hands (58) 11 March 1940 in Jadebusen by an RAF Blenheim bomber. Raised in March 1940, repaired and returned to service. * See note

Sunk again on 2 November 1940 NW of Ireland by depth charges from the destroyer HMS Antelope. 2 dead and 44 survivors.

* I think it's kind of odd they would raise a U-Boat with all hands still on board. Now, it's considered a tomb, a final resting place, and left alone. Any ideas as to why they would have done that?

Probably for the same reason they'd tow away and repair a knocked out panzer with a dead crew on the battlefield (which happened a lot) Fixing it is still quicker and cheaper than building a new one. In addition, you can return the crew's remains for burial at home. I doubt if many family members would object as opposed to they're being entombed in a U-Boat somewhere out at sea.

Although briefly decommissioned, the US put the sunken submarine Squalus back into service despite the 26 deaths on board. (and the Confederate Hunley was repeatedly raised despite killing every crew that trained on her)