Any diver knows better than to touch living coral, but, unfortunately, some do it anyway. Consequently, some dive operations prohibit divers from wearing gloves. The thinking is that if you don't have gloves on, you won't touch coral so you don't get stung, cut or burned.
Unfortunately, that leaves hands unprotected when you're climbing a rusty ladder or clinging to an encrusted mooring line during a safety stop. A better alternative is to cut the fingertips off your reef gloves. This allows you to hang onto an encrusted mooring line, for example, but not claw your way along the coral. Another benefit is that it restores some of your dexterity.