In some of the recent research trying to locate and photograph giant squid they discovered that sperm whales actually feed on the giant squid. When they then started looking at the whale they found that most, it not all, have huge scars like the ones in the picture all over their heads from fighting with giant squid. Some of the scars a HUGE.
http://en.wikipedia.org/wiki/Sperm_whale
Or, it could have been a US submarine!
