"Survive the Savage Sea", published sometime in the 1970s. English family sells their dairy farm and goes to sea in a 40-ish wooden sailboat. Somewhere out from Panama, they're stove in by whales, orcas (killer whales), they believed. (But the book is really about the family's survival ordeal, amazing in itself, for over a month in weakening raft.) I think people have expressed doubt about whether they were actually attacked, however, i.e., whether that kind of behavior is normal or even common in those whales...no one there to record it on video (But there are stories of large ships being sunk by sperm whales after being rammed.)