what is the equivalent of a colonel in the navy
Colonel (United States) In the United States Army, Marine Corps, and Air Force, colonel /ˈkɜːrrnəl/ is the most senior field grade military officer rank, immediately above the rank of lieutenant colonel and immediately below the rank of brigadier general. It is equivalent to the naval rank of captain in the other uniformed services.[n 1] The pay grade for colonel is O-6.
Corporal In some militaries, the rank of corporal nominally corresponds to commanding a section or squad of soldiers. However, in the United States Army, the rank of corporal is considered a "lateral promotion" from E-4 Specialist and usually only occurs when the soldier has been selected by a promotion board to become an E-5 Sergeant and is serving in an E-5 billet such as a fireteam leader in a rifle squad. The lateral promotion is used to make the soldier a non-commissioned officer without changing the soldier's pay. As the Table of Organization & Equipment (TO&E) rank of a fire team leader is sergeant and that of squad leader is staff sergeant. In the United States Marine Corps, corporal is the Table of Organization (TO) rank for a rifle fire team leader, machine gun team leader, light mortar squad leader, and assault weapon squad leader, as well as gunner on most larger crew served weapons (i.e. medium mortars, heavy machine guns, and anti-tank missiles), armored vehicles (e.g. tanks, light armored vehicles, and armored assault vehicles), and the two assistant gunners on a howitzer (the gunner is a sergeant).