Able Seaman (AB)
An Able Seaman (AB), or Able Bodied Seaman, is an experienced and certificated deck rating — a skilled member of the deck crew ranking above the Ordinary Seaman (OS). To hold the rank, a seafarer must have accumulated sea service and gained certification under the STCW standards, demonstrating competence in seamanship.
An AB's duties include steering the ship (helm), keeping a proper lookout on watch, mooring and anchor operations, cargo work, and the full range of deck maintenance — splicing and handling ropes and wires, rigging, chipping and painting, and operating deck machinery. ABs form the experienced backbone of the deck crew, working under the Bosun and deck officers. The rank is a key step in the deck rating career path (OS → AB), and ABs are essential to watchkeeping, safe navigation (as helmsman and lookout) and the practical seamanship that keeps a ship operating. They are a fundamental part of the ship's crew.
The Able Seaman is the skilled workhorse of the deck — steering the ship, standing lookout, handling lines and doing the seamanship that keeps her safe and maintained. Certificated under STCW and experienced, ABs are the backbone of the deck crew and essential to safe watchkeeping and navigation.
What is the difference between an AB and an Ordinary Seaman?
An Able Seaman is more experienced and certificated under STCW, with skilled duties like helm and lookout; an Ordinary Seaman is a more junior deck rating.
What does an Able Seaman do?
Steers the ship, keeps lookout, handles mooring and anchor work, assists cargo operations and carries out deck maintenance.