Go to the Great Barrier Reef and drop into the water just outside of the reef. Cut yourself a couple of times across the upper arms and then swim like hell for the shore. It's called bleeding in front of sharks.
Man that doesn’t sound like fun at all. Sounds like a lonely bleedout, drowing, or getting eaten.
I think getting all boozed up and running through the streets of Spain with thousands of spectators, dodging bulls and hundreds of other runners in a madhouse dash has far far more appeal.
As I said, if I were younger and was in Spain, I’d jump out there for a thrill.
Enjoy that bleedy shark swim thing you like though.
When I was 19/20, (1969-70), I dodged rockets and satchel charges for a year.