Sea-divers wear specially designed swim-suit. Why?

Sea divers need to wear specially designed swim-suit because in deep sea, the total pressure exerted on the diver's body is much more than his blood pressure. To withstand it, they need to wear a specially designed swim-suit, made from glass reinforced plastic or cast aluminium. The pressure inside the suit is maintained at one atmosphere. This allows the diver to withstand the enormous external pressure and be safe underwater.