Besides shit that anyone with any sort of intelligence would be afraid of such as mother nature, no not that I can think of off the top of my head. Do I go swimming in the ocean, no I'm not dumb, that's not fear, that should be common sense. But in my opinion, that's an entirely different world and doesn't count until we've discovered the remaining 95% of it...We all remember what happened to Steve Irwin, right?
Are you one of those people who just dives into the ocean for a dip? (The beach doesn't count, I'll swim at the beach as long as I'm aware of the sea life in the area)