Bear Grylls not draining

Watching the shows I really like to watch at water and Bear swimming even in the coldest places on Earth.
He sometimes keeps his clothes dry to wear after swimming and to keep himself warm - thats very reasonable, but... He does not have a towel or its just not shown... Whats the use of dry clothes if body is not dry? He swims in his boxers and in the next scene wears dry trousers on them. And he does not have a wet ass!!! That surprizes me. How can he get dry and drain a peace of clothe sooo fast?
BEIGAS / END