The best place to find live velvet swimming crabs is underwater, they are often too large to remain in rock pools. Velvet swimming crab shells are occasionally washed up on beaches; these may be dead animals or the carapace which is shed to allow the crab to grow. The small crabs which appear around piers and sea defences are often shore or harbour crabs but velvet swimming crabs may appear in these places. Divers and snorkelers can expect to see these crabs at all depths.