Master Diver

Master Diver usually refers to an experienced person in underwater diving or scuba diving. In more formal settings, this may refer to someone who has completed a qualification program to receive the designation.

United States military

 * Master diver (United States Navy)
 * United States Army Master Diver, a qualification of United States Army engineer diver

Recreational diving

 * Master Scuba Diver, a non-professional certification
 * Divemaster, a professional certification