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.
Admiral (Australia) Admiral (abbreviated as ADML) is the highest active rank of the Royal Australian Navy and was created as a direct equivalent of the British Navy rank of admiral. It is a four-star rank. Since World War II, in general, the only time the rank is held is when the Chief of the Defence Force is a navy officer.