This is the northern kelp crab (Puggetia producta). Most crabs are nocturnal, these crabs are not. They are not or not very well camouflaged and I have seen a lot of these kelp crabs in the open. Like this one clinging on bull kelp (hence the name of the crab). Kelp crabs are the second favourite food of otters. Then why don’t they hide or come out at night as ‘normal’ crabs?
Northern kelp crab clinging on bull kelp in a strong current.
This old(er) crab has lost a few walking legs and one claw. When a crab sheds his armour to grow, he can regenerate lost legs, claws and other parts.