312.30. Protection against electrical hazards: Electric voltage of devices, equipment and tools used underwater must not exceed 110 V in direct current or 42 V in alternating current.
Those devices, equipment and tools must be(1) insulated;
(2) equipped with a shut-off switch;
(3) equipped with a ground fault detector if the power supply is alternating current from the public network or its equivalent; and
(4) grounded, in the case of equipment.