Grand Admiral a naval rank in one of the highest in the several European navies that use this system, what system are they using?
Military rank Military ranks are a system of hierarchical relationships in armed forces, police, intelligence agencies or other institutions organized along military lines. Usually, uniforms denote the bearer's rank by particular insignia affixed to the uniforms. Ranking systems have been known for most of military history to be advantageous for military operations, in particular with regards to logistics, command, and coordination; as time went on and military operations became larger and more complex, military ranks increased and ranking systems themselves became more complex.
Captain Captain and chief officer are overlapping terms, formal or informal, for the commander of a military unit, the commander of a ship, airplane, spacecraft, or other vessel, or the commander of a port, fire department or police department, election precinct, etc. Captain is a military rank in armies, navies, coast guards, etc., typically at the level of an officer commanding a company of infantry, a ship, or a battery of artillery, or similar distinct unit. Chief officer may be used interchangeably with captain in some situations, as when a Captain-ranked Navy officer is serving as the commander of a ship. The terms also may be used as an informal or honorary title for persons in similar commanding roles. In mining (esp. Cornish), it is an honorific given the superintendent or manager of a mine.