The U-612 used during filming is a non-diving u-boat replica of the US Navy submarine S-33 built in Valetta, Malta. It was heavily modified but is the same watercraft used for U-571 (2000).
I've got no problem with updates, re-interpretations or for that matter complete revisions of prior works and narratives. In my mind it is perfectly fine to take a Shakespeare play and tell it a completely different way.
That said this "sequel" to Das Boot is absolutely terrible. it is simply a strange soap opera.
