Able Seafarer Deck (AB)  – Your first position on a vessel will be an Ordinary Deckhand. After completing the Able Seafarer (Deck) learning opportunity you are required to obtain 18 months sea service in order to obtain your Able Seafarer Deck qualification and seaman’s book. Your sea service and task book must reflect your time and job function on a particular vessel. After occupying the position of an Able Seaman you may be appointed as a Bosun, the person in charge of Deck Operations.