It's not on the Superbit either.
There has been no BluRay release of Das Boot for North America AFAIK - Amazon.com has no listing for it, not even one to indicate that it's in the works but not yet available.
Someone posted a link to one here a while back for one though - I just found it again on Amazon.de, due to be released next Tuesday. German language only, judging by the info provided... to tell you the truth if I could buy it I would just to have the subtitles in German which would be way cool.
But then I'd have to buy a Blu-Ray player, lol. And do Blu-Ray discs come in different regional formats like DVDs? Cuz then there'd be that to consider as well.
Hmm... wonder if I could find a DVD version with German subtitles. I already have a multi-region DVD player.