Seaman

Common military ranks in English
Navies	Armies	Air forces
Commissioned and Non-commissioned officers
Admiral of the fleet	Marshal or Field marshal	Marshal of the air force
Admiral	General	Air chief marshal
Vice admiral	Lieutenant general	Air marshal
Rear admiral	Major general	Air vice-marshal
Commodore	Brigadier or Brigadier general	Air commodore
Captain	Colonel	Group captain
Commander	Lieutenant colonel	Wing commander
Lieutenant commander	Major or Commandant	Squadron leader
Lieutenant	Captain	Flight lieutenant
Sub-lieutenant	Lieutenant or First lieutenant	Flying officer
Ensign	Second lieutenant	Pilot officer
Midshipman	Officer cadet	Flight cadet
Enlisted grades
Warrant officer or Chief petty officer	Warrant officer or Sergeant major	Warrant officer
Petty officer	Sergeant	Sergeant
Leading seaman	Corporal	Corporal
Seaman	Private	Aircraftman

Seaman is a naval rank and is either the lowest or one of the lowest ranks in most navies around the world. In the Commonwealth it is the lowest rank in the navy. The next rank up is able seaman, followed by leading seaman, which is followed by the petty officer ranks.

In the United States, it means the lowest three enlisted rates of the U.S. Navy and U.S. Coast Guard, followed by the higher petty officer ranks. The equivalent of the seaman is the matelot in French-speaking countries, and Matrose in German-speaking countries.

The term "seaman" is also a general-purpose for a man or a woman who works anywhere on board a modern ship, including in the engine spaces, which is the very opposite of sailing. This is untrue in the US Navy where a sailor might be a seaman but not all US Navy sailors are a 'Seaman' as they might be an Airman, Fireman, Contructionman, or Hospital Corpsman. Furthermore, "seaman" is a short form for the status of an "able-bodied seaman," either in the navies or in the merchant marines. An able-bodied seaman is one who is fully trained and qualified to work on the decks and superstructure of modern ships, even during foul weather, whereas less-qualified sailors are restricted to remaining within the ship during times of foul weather — lest they be swept overboard by the stormy seas or by the high winds.

There are 4 grades of seaman/matelot in the Royal Canadian Navy:

Ordinary seaman or matelot de troisième classe

Able seaman or matelot de deuxième classe

Leading seaman or matelot de première classe

Master seaman or matelot-chef

The rank of master seaman is unique because it was created only for the Canadian Navy. It does not follow the British tradition of other Canadian ranks. It corresponds to the rank of master corporal/caporal-chef.

Matelot 2e classe (seaman 2nd class), or apprentice seaman, and matelot breveté (able seaman) are designations of the French Navy. Matelots are colloquially known as "mousses".

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Wikipedia