ES · EN · PT

IMO / STCW · Merchant Vessel · Deck

Ordinary Seaman (OS)

Also known as: Ordinary Seaman · OS · Deckhand

Entry-level operational role in the deck team.

What you need to perform it

Primary qualification

  • Rating forming part of a navigational watch certificate — STCW Regulation II/4 (section A-II/4), when performing watch duties
  • Spain: Marinero de Puente proficiency certificate (Order FOM/2296/2002), issued by the DGMM, with the Seaman's Book

Basic STCW

  • STCW A-VI/1 Basic Safety Training and onboard safety familiarisation
  • Valid seafarer medical certificate (in Spain, ISM medical examination)

Specific courses

  • Lookout and helmsman duties: standard helm orders and watchkeeping rules of the STCW Code (A-VIII/2)
  • Mooring safety (snap-back zones), enclosed spaces and working aloft, per the company's safety management system

Indicative experience

Regulation II/4: minimum age 16 and seagoing service including approved training and experience of ≥ 6 months, or special prior training plus ≥ 2 months at sea. Promotion to Able Seafarer Deck (Regulation II/5) requires ≥ 18 months of service as a watch rating, or ≥ 12 months with approved training.

Observations

Progression route: Ordinary Seaman (II/4) → Able Seafarer Deck (II/5) → Bosun; the path to officer requires returning to the academic route. The real trade is learned on deck: splicing, surface treatment and PPE discipline. In mooring operations the newcomer's golden rule is position: never inside the bight of a line nor in the snap-back zone.

What this role does

DepartmentDeck
GroupDeck Ratings
Role typeRating
Reports toBoatswain/Able Seaman
SupervisesNot applicable

Entry rating of the deck department: always works under the direction of the Bosun or an AB in maintenance (chipping, painting, greasing), mooring operations and lookout duties. If forming part of the navigational watch, the STCW Regulation II/4 certificate is required. In Spain, the Marinero de Puente certificate (Order FOM/2296/2002) is the usual signing-on route. It is the step where the sea months that open promotion to Able Seafarer are accumulated.

Typical watches

  • Support watch for assigned tasks

Key responsibilities

  • Basic deck, cleaning and maintenance support.
  • Assistance in mooring maneuvers.
  • Lookout and safety support as assigned.

Operational scope

  • Basic deck support
  • Cleaning
  • Mooring assistance

Profile reviewed by HydroAbyss (2026). Cited rules and timeframes are indicative: the final requirement is set by the flag State, the Administration and each company.