1. sitting on the nose of the board while on a wave.
2. resting on the board after a good wave
It refers both to 10 toes dangling and to the perfect score of a judged sporting event, which would definitely be attained by hanging 10.
2) -Whatcha doin out here? That big one was the last wave.
-Eh, just hangin 10.
made with vodka, pineapple juice, cranberry juice, lime juice, and seltzer. Perfect for bored kids in NYC who wanna get drunk the klassy way.
alex: "aww honey calm down and drink a hang 10"
Weird Guy: Hey, wanna see me hang 10
You: but you don't have a surf board and you're wearing a trench coat.
Weird Guy: (opens trench coat) I'm Hangin 10 right now!