I was fishing with my dad 30 years ago in Cabo San Lucas when we sighted a whale shark. My old man told me to jump in and ride it. I looked at him like "WTH?". He screamed "Don't you ever want to have fun in your life?!" So I had no choice in the matter. Jumped in, and held it's fin until I ran out of breath.
Man, wouldn't your dad feel bad if it turned-out being a mutant Carnivorous whale shark!