Friendly? I wouldn't say that, but they are no threat to humans at all. Whale sharks don't even have teeth. They eat plankton and tiny fish. This one was feeding on the surface when we found her. Granted they get to be 50-60 feet long, this one was about 40, and could certainly do damage if they wanted to but they totally ignored us. You do have to get out of their way, they can't see straight ahead so if you're in front you could get bumped. We saw 14 of these in 3 days in Galapagos.