The insignia of the submarine service is a submarine flanked by two dolphins. Dolphins, traditional attendants to Poseidon, Greek god of the sea and patron deity of sailors, are symbolic of a calm sea and are sometimes called the "sailor's friend."
The origin of the insignia dates back to 1912. On June 13, CAPT Ernest J. King, commander Submarine Division 3, later a World War II fleet admiral and Chief of Naval Operations, suggested to then-Secretary of the Navy George von L. Meyer, via the Bureau of Navigation (now the Bureau of Naval Personnel), that a distinguishing device for qualified submariners be adopted.
He submitted his pen and ink sketch showing a shield mounted on the beam ends of a submarine with dolphins forward and aft of the conning tower. The suggestion was strongly endorsed by Commander submarine division Atlantic.
A Philadelphia firm, previously contracted by the Navy, was also asked to design a suitable badge. The firm submitted two designs which were combined into the single design used today. It consisted of a bow view of a submarine cruising on the surface, with bow planes rigged for diving flanked by dolphins in a horizontal position with their heads resting on the upper edges of the bow planes.
By March 29, 1924, the Chief of Navigation recommended to SecNav that the design be adopted. Theodore Roosevelt Jr., then acting SecNav, approved the recommendation.
Originally, the insignia was to be worn at all times by officers and enlisted men qualified in submarine duty attached to submarine units or organizations ashore or afloat, and not to be worn when not attached.
The officers' insignia was a bronze, gold-plated pin, worn centered above the left breast pocket and above ribbons or medals. Enlisted men wore the insignia embroidered on silk, in white on blue for blue clothing, blue on white for white clothing. This was sewn on the outside of the right sleeve, midway between the wrist and the elbow. The device was 2.7 inches long.
In mid-1947, the embroidered device shifted from the sleeve of the enlisted men's jumper to above the left breast pocket. A change to uniform regulations dated Sept. 21, 1950, authorized the embroidered insignia for officers and a bronze, silver-plated pin-on for enlisted men.
The wearing of the embroidered Pin-on devices by officers and enlisted men, on the coat of service dress blue, full dress white, dinner dress blue and dinner dress white jackets and aviation green working uniforms was authorized in the 1981 Uniform Regulations.
The devices are also worn on the khaki shirt, and the long sleeve blue and summer white shirts. The embroidered device's background material also must match the color of the uniform on which it is worn.