Officer of the Deck

Officer of the deck (OOD) is a position in the United States Navy and United States Coast Guard that confers certain authority and responsibility. The officer of the deck on a ship is the direct representative of the captain, having responsibility for the ship.

In port, the OOD is stationed on the quarterdeck, with a qualified petty officer manning the brow. The petty officer manning the brow is called the petty officer of the watch, or POOW. The POOW is in the position of managing who comes and goes, as well as security.

At sea, the officer of the deck is stationed on the bridge and is in charge of navigation and safety of the ship, unless relieved by the captain or a senior qualified line officer. The officer of the deck is assisted by the junior officer of the deck, who is in the process of qualifying as full officer of the deck, and the conning officer, who is also training to become an OOD, but is directly responsible for the maneuvering of the ship. The following positions also assist the officer of the deck on the bridge: boatswain's mate of the watch (BMOW), quartermaster of the watch (QMOW), and signalman of the watch (SMOW).

The following is a list of the OOD's primary duties as prescribed by the Standard Organization and Regulations of the United States Navy, OPNAVINST 3120.32

There is also a very formal method for relieving the officer of the deck.

Assume that Lieutenant Smith is the officer of the deck and Lieutenant Doe is his replacement. Lieutenant Doe will check into the Combat Information Center (CIC) to determine any necessary actions that will be expected to occur during the watch, check the navigational track, read any orders, and determine the position of all nearby ships. After this is complete, Lieutenant Doe will state to Lieutenant Smith, "I am ready to relieve you, sir." Lieutenant Smith states, "I am ready to be relieved." He will then brief Lieutenant Doe on any additional information that the replacement should be made aware of, reconfirming the information that Lieutenant Doe has previously gained on his own. When Lieutenant Doe is fully satisfied, he then states, "I relieve you, sir." Lieutenant Smith then states, "I stand relieved. Attention in the pilot house (or bridge), Lieutenant Doe has the deck." An exchange of hand salutes would also be appropriate, depending on the ship. Lieutenant Doe would then announce, "This is Lieutenant Doe, I have the deck." (The use of the term sir in the manner indicated occurs without regard to the actual ranks held by the officers.)

...
Wikipedia