Submarine Qualification insignia (usually known as "dolphins" or "fish") are breast insignia of the submarine warfare community which are issued to those naval personnel after they complete a complex, demanding and extensive program that incorporates learning each system aboard the submarine and completion of certain watchstanding requirements including cross rate watch requirements. This program differs from many of the other "Warfare" programs in that it requires personnel to become proficient in engineering and operational details to such an extent that each person must be able to understand and perform basic operation of each system and equipment aboard the submarine. In addition each person must be able to efficiently perform damage control and emergency control functions in each space on the submarine.
In addition to line officer and enlisted versions, there are insignia for officers working in engineering duty, medical corps, and supply corps.