Officer in tactical command

In NATO, the officer in tactical command (OTC) is the naval officer exercising tactical command of a group of ships in a tactical formation such as a task unit, task group, or task force.

Ships travelling together on a specific mission might have one of the commanding officers designated OTC. On occasion, an officer senior to the ships' captains (a senior captain, a commodore, or an admiral) will be embarked specifically to take command of the formation, and in this case, he or she will exercise the function of OTC.