when you are stung, use vinegar.... it neutralises the stings...
which will still hurt even when the damned thing is dead...
always bring a bottle with you when going to the sea..
if you do not have, piss on the stung area.. not as effective but
it works...
oh, btw, one world class surfer disappeared a long time ago.. he
was suspected to have been eaten by a shark as the beach he was
surfing at was full of Great Whites