During the ICEX 2003 naval exercises near the North Pole, the American submarine Connecticut (SSN 22) poked it's sail and rudder through the ice. When an officer looked around outside via the periscope, he noted that his sub was being stalked by a hostile polar bear. The periscope cam was turned on, and these photos of a polar bear chewing on the subs rear rudder resulted. The damage was said to be minor. The SSN 22 is a Seawolf class boat, one of the navy's newest submarines. It wasn't designed as a polar bear snack, but that's how life is sometimes.
Just a note, there are only three Seawolf-class boats- the SSN-21 Seawolf, SSN-22 Conneticut, and SSN-23 Jimmy Carter (which is still being built).
