I've swam with dolphins in the FL keys, really cool.  And I swam with sharks @ Coral World, Nassau, the Bahamas, that's pretty neat, too.  Obviously they were very small, harmless ones.  About 5 years ago I was in the ocean @ Assateague National Seashore (Ocean City, MD) when there was a group small sand sharks (totally harmless) swimming around in the water near the shore.  Most of the people weren't getting too excited about it, but a few had to do the, "Shark! Shark!" thing so the lifeguards made everyone get out of the water 'til the sharks moved down the coast.  As your mother said, seeing a whale coming up out of the water is totally awesome.  Those guys are big!