A communications officer is a naval

line officer A line officer or officer of the line is, opposed to staff officers or reserve officers, a military officer who is eligible for command of operational, tactical or combat units. The name most likely stems from the Early modern warfare tactics ...

responsible for supervising operation and maintenance of a

warship A warship or combatant ship is a naval ship that is used for naval warfare. Usually they belong to the navy branch of the armed forces of a nation, though they have also been operated by individuals, cooperatives and corporations. As well as b ...

signal flags International maritime signal flags are various flags used to communicate with ships. The principal system of flags and associated codes is the International Code of Signals. Various navies have flag systems with additional flags and codes, and ...

signal lamp Signal lamp training during World War II A signal lamp (sometimes called an Aldis lamp or a Morse lamp) is a visual signaling device for optical communication by flashes of a lamp, typically using Morse code. The idea of flashing dots and dashes ...

s, and radio

transmitter In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an antenna (radio), antenna with the purpose of sig ...

s and receivers. The communications officer is usually responsible for encrypting and decrypting secret message traffic and for distribution and safe storage of secret messages. Aboard some ships, the communications officer is responsible for the ship's secret publications inventory or for the ship's

post office A post office is a public facility and a retailer that provides mail services, such as accepting letter (message), letters and parcel (package), parcels, providing post office boxes, and selling postage stamps, packaging, and stationery. Post o ...

and distribution of mail.

United States Navy

In the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

, communications officers are referred to as a COMMO.

Royal Canadian Navy

In the

Royal Canadian Navy The Royal Canadian Navy (RCN; , ''MRC'') is the Navy, naval force of Canada. The navy is one of three environmental commands within the Canadian Armed Forces. As of February 2024, the RCN operates 12 s, 12 s, 4 s, 4 s, 8 s, and several auxiliary ...

, this role is filled by the Communication and Information Systems Officer (CISO). This is a trained Naval Warfare Officer (NWO) who fulfils three roles at sea: Bridge Watchkeeper, divisional officer for the Naval Communicators, and custodian of the cryptographic keying material ( COMSEC). CISOs will generally have 3–5 years' experience at sea as watchkeepers, as well as a 4–5 month course focusing on communications systems equipment, policy, and procedure.

Sources

{{reflist Military ranks