Able seaman (rank)

In the British Royal Navy in the middle of the 18th century, the term able seaman (abbreviated AB) referred to a seaman with at least two years' experience at sea. Seamen with less experience were referred to as landmen or ordinary seamen.

Royal Navy
In 1653 the Royal Navy introduced a new pay scale as part of reforms following defeat in the Battle of Dungeness the previous year. Included in these reforms were, for the first time, separate pay scales for more experienced seamen. It distinguished between an ordinary seaman and an able seaman. The higher ranked able seaman could steer, use the lead and work aloft, traditionally to “hand, reef, and steer.” An able seaman received about 25% higher pay than an ordinary seaman.

In time of war (such as the Seven Years' War or the Napoleonic Wars), with many more warships in service, the navy, merchant marine, and privateers competed ferociously for the limited pool of able seamen, leading to the unpopular use of impressment by the Royal Navy to keep its ships manned. In peacetime, with fewer active warships, there was usually a surplus of unemployed able seamen willing to work in the navy. As late as the Napoleonic Wars, the Royal Navy's practice of stopping American ships to press American sailors into involuntary service was one of the main factors leading to the War of 1812 with the United States.

Notable able seamen
Some notable able seamen from the Royal Navy include:
 * Simon (cat), ship's cat on HMS Amethyst, promoted to able seaman in the Royal Navy. Also said to have been promoted to "able seacat"
 * Just Nuisance, a Great Dane in the Royal Navy, famous for his dislike of officers and liking of ordinary sailors.
 * Alistair MacLean, author
 * Sir Fairfax Moresby, English admiral of the Fleet, entered the Navy as an AB
 * William Charles Williams, recipient of the Victoria Cross
 * William G. V. Williams, first recorded Australian casualty in World War 1. He was actually part of the Royal Australian Navy and was an able seaman. He died on 11 September 1914 in Rabaul, Papua New Guinea as part of the Australian expeditionary force that captured the former German colony called German New Guinea. He is buried in the Rabaul (Bita Paka) War Cemetery in Kopoko that is near Rabaul on the island of New Britain, being part of Papua New Guinea.
 * George Hinckley, recipient of the Victoria Cross
 * William Bligh, best known as "Captain Bligh" for the famous mutiny that occurred against his command aboard HMS Bounty, entered the Royal Navy as an able seaman
 * Admiral of the Fleet Sir Provo William Perry Wallis entered the Navy as an able seaman at age four
 * William Alfred Savage, recipient of the Victoria Cross
 * Albert Edward McKenzie, recipient of the Victoria Cross
 * Edward Robinson, recipient of the Victoria Cross
 * Sir John Borlase Warren, 1st Baronet, English admiral, entered the Navy as an able seaman
 * Michael Byrne, signed as an able seaman by Captain Bligh on the Bounty primarily to play the fiddle
 * Matthew Quintal, able seaman and mutineer aboard HMS Bounty
 * Kate Nesbitt, first female recipient of the Military Cross in the Royal Navy

Royal Canadian Navy
In the Royal Canadian Navy, able seaman (AB) is the second-lowest of the non-commissioned member ranks, ranking above ordinary seaman and below leading seaman. Able seamen wear a single gold chevron, point down, as an insignia of rank; it is worn on the upper part of both sleeves of the service dress tunic, and on slip-ons on both shoulders on other uniforms.

In all trades, the rank is awarded on completion of 30 months of service, by which time all initial training is completed. Consequently, it is sometimes said that promotion to the rank of Able Seaman means the recipient has lost their 'best excuse', on the theory that Ordinary Seamen are generally assumed to know nothing.

Able seaman is the equivalent rank to private (trained), or simply private, in the Army and Air Force. In French the rank is called matelot de 2e classe.