Finn/jack harries

it‘s him. as @trixy189 already said it has to be him because the other guy is hairy and has a beard. the guy in the pic is mostly smooth (as is jack). plus they were only two on this journey so it can‘t be any other person
 
it‘s him. as @trixy189 already said it has to be him because the other guy is hairy and has a beard. the guy in the pic is mostly smooth (as is jack). plus they were only two on this journey so it can‘t be any other person

I hope it's him, but it could just be the water making his mate look less hairy. Also, as it took two years to film, they may both have had varying amounts of facial hair.