Naval Regulations and Code of Conduct, Revision of 2087
“When a commander in the Theater of Operations has data essential to the preservation of the main body of Naval forces, and communication with his superiors is restricted through no act or omission of his own, he may relieve his superior and assume command of all forces in the theater for the duration of the emergency. In order that authority not be divided or contested, the superior must allow the temporary usurpation of his authority. No challenge may be made to the assumption of command by any other officer under said superior, or any officer not in the theater. However, upon conclusion of the emergency the relieving officer must show by incontrovertible and conclusive evidence that his usurpation of authority was essential to preserve the main body of Naval forces. The penalty for wrongful usurpation is death. Any such sentence, once imposed, may not be appealed, commuted, or pardoned.”
Command of any work detail may be delegated by the Captain or the officer of the watch to any lieutenant, midshipman, or other officer in his command.
The following persons are not line officers within the meaning of these regulations: a Ship’s Doctor, a chaplain, a Pilot, and an Engineer. All other officers are line officers within the meaning of these regulations.
The Captain of a vessel may from time to time appoint a midshipman, who shall serve in such capacity as the Captain and his officers may from time to time direct.
The Captain of a vessel may relieve himself of command when disabled and unfit for duty by reason of mental illness or physical sickness or injury. Upon his certification of such action in the Log, his rank of Captain shall be suspended and command shall devolve on the next ranking line officer.
In case of death or disability of the Captain, his duties authority and title shall devolve on the next ranking line officer.
Every watch not commanded by the Captain shall be commanded by a commissioned officer under his direction.