Man drop a link I have to read this
Didn't read it, was watching a show on Discovery or NAtGeo and a Navy Capt was talking about how they were doing maintenance on one of their subs and they started to notice these suction marks on the hull....they assume it was a giant squid, I would tend to agree being that they're known to attack Sperm Whales which can dive deeper than any sub we have and whose hide is denser than the hull of one of those subs, I'll see if I can find the Doc.