Life on Board: Ships, Rotations and Roles

Prerequisites

Read the earlier lessons in this course, especially the routes into the Merchant Navy. Experience of living aboard a yacht on passage helps, but a ship is a workplace with a legal framework for your contract, rest, pay and cabin, and this lesson introduces it.

Learning Objectives

• Describe the main ship types and how life differs between them.
• Explain typical rotations, the watch system and what the rest-hour rules mean in practice.
• Know the roles of the deck, engine and catering departments and the path from cadet to master.
• Know your main rights under the Maritime Labour Convention 2006 (MLC): employment agreement, hours of rest, leave, repatriation, accommodation and medical care.
• Recognise the everyday hazards of shipboard work and where the Code of Safe Working Practices fits in.

Ship Types

• Container ships: fast, tight port schedules, short port stays (often under 24 hours), so little shore leave.
• Bulk carriers: long ocean passages and sometimes weeks waiting at anchor; ports may be remote.
• Tankers (crude, product, chemical): long passages and demanding cargo, inerting and tank-cleaning procedures; extra tanker safety certificates are required.
• Gas carriers (LNG, LPG): highly technical, strict procedures, well paid.
• Ferries and ro-ro: short crossings, many port calls a day, often home regularly.
• Cruise ships: large crews, many passengers and a hotel department bigger than the marine one.
• Offshore: supply, anchor handling, wind farm and survey vessels, often with dynamic positioning (DP) and fixed rotations.

Rotations and Contracts

Seafarers work in trips or tours. Officer rotations range from equal time on and off on ferries and offshore (for example 2 weeks on and 2 off, or 4 and 4) to three to six months on deep-sea ships. Ratings in some fleets serve longer contracts, commonly 6 to 9 months.

The MLC sets the limits around this:

• Every seafarer must have a signed seafarers' employment agreement (SEA) that they have had the chance to review and take advice on, with a copy kept by the seafarer (MLC Reg 2.1). It states pay, leave, the termination notice period and repatriation entitlement.
• Paid annual leave is at least 2.5 calendar days per month of employment, and agreements to give up the minimum leave are generally prohibited (MLC Standard A2.4).
• Repatriation at no cost to the seafarer is due when the contract expires abroad, when it is ended by the shipowner or justifiably by the seafarer, or when the seafarer can no longer work. The maximum service period before repatriation must be under 12 months, and the shipowner must hold financial security for repatriation and abandonment (MLC Reg 2.5, Standard A2.5.1 and A2.5.2).
• The minimum age is 16, and night work for under-18s is prohibited (with limited training exceptions), where night means at least nine hours covering midnight to 5 a.m. (MLC Standard A1.1).

Watches and Hours of Rest

Deep-sea ships usually keep three watches of four hours on and eight off. By custom the Second Officer keeps the 12 to 4 (the navigator), the Chief Officer the 4 to 8 (so they can manage the deck during the day and take star sights at twilight), and the Third Officer the 8 to 12. Each bridge watch has an officer and a lookout. Short-sea ships with only two watchkeeping officers often run six on, six off, which is hard on sleep.

The rest rules apply to everyone on board, not only watchkeepers (MLC Reg 2.3 and Standard A2.3; in the UK, the Merchant Shipping (Hours of Work) Regulations):

Some practical consequences:

• Drills must be run in a way that minimises disturbance of rest and does not cause fatigue (Standard A2.3, para 7).
• If you are on call, for example the duty engineer in an unmanned machinery space, and are called out during rest, you are owed adequate compensatory rest (para 8).
• A table of shipboard working arrangements must be posted, and daily records of hours of work or rest kept; you get a copy signed by the master and by you (paras 10 to 12). Record honestly: falsified rest records hide fatigue and are a common port state control finding.
• The master may suspend the schedule for the immediate safety of the ship, people or cargo, or to help others in distress, but must give adequate rest afterwards (para 14).

A one-in-three pattern (four on, eight off) gives two eight-hour rest periods a day, comfortably above the minimum until day work, cargo operations and drills eat into them. Six on, six off gives two six-hour rest periods, which meets the minimum exactly, with no slack at all for port work or drills.

The Departments

• Deck: the Master, Chief Officer (Chief Mate), Second and Third Officers and deck cadets, plus ratings: the bosun, able seafarers (AB) and ordinary seafarers (OS). Navigation, cargo, stability, mooring, lifesaving and firefighting equipment, maintenance.
• Engine: the Chief Engineer, Second Engineer, Third and Fourth Engineers, the electro-technical officer (ETO), engine cadets and ratings (fitters, motormen, wipers). Propulsion, power generation and all machinery.
• Catering and hotel: chief cook, cooks and stewards; on cruise ships a large hotel department.

The Master and Chief Engineer are the two senior officers. The Chief Officer is the master's deputy, in charge of cargo and the deck department, and usually the ship's safety officer.

From cadet to master

The UK deck route is set out in MSN 1856. A cadet completes at least 12 months of approved sea service documented in a Training Record Book, including 6 months on bridge watchkeeping duties, plus college study and short courses, to qualify as OOW (STCW II/1). An experienced rating route needs 36 months at sea with 6 months of bridge watchkeeping. Chief Mate unlimited (II/2) then needs 12 months as OOW, and Master unlimited needs 36 months as OOW, reduced to 24 months if at least 12 months were served as Chief Mate (MSN 1856, section 3).

Living Conditions

The MLC (Reg 3.1 and Standard A3.1) sets out what a cabin must provide:

• On ships other than passenger ships, an individual cabin for each seafarer (exemptions possible on ships under 3,000 GT and special-purpose ships), separate cabins for men and women, and a separate berth of at least 198 cm by 80 cm.
• Minimum floor area for a single cabin: 4.5 square metres under 3,000 GT, 5.5 square metres from 3,000 to 10,000 GT, and 7 square metres above 10,000 GT; officers' cabins are larger.
• Proper heating, ventilation, lighting, sanitary facilities, a mess room, recreational facilities, and food and drinking water of good quality supplied free of charge (Reg 3.2).
• Medical care on board and ashore at no cost, with prompt access to a doctor or dentist in port and a medical chest and trained person aboard (Reg 4.1).

In practice you can expect a private cabin as an officer, internet access that varies from good to almost none, a multinational crew with English as the working language, and long periods where your shipmates are your whole social world. Isolation and fatigue are real health risks: welfare facilities, shore leave and good onboard relations matter.

Working Safely on Deck

UK ships follow the Code of Safe Working Practices for Merchant Seafarers (COSWP), the authoritative best-practice manual on health and safety at sea. A new edition was issued on 16 March 2026; it is now a bound book reissued when needed rather than amended annually, and the 2026 changes revised the ISM sections, enclosed-space drills (which must now consider shore staff or third parties in the space), enclosed-space entry and lifting equipment maintenance (MIN 688 Amendment 5). The next edition is due in 2028.

Mooring and towing are among the most dangerous jobs a new seafarer does. In MAIB Safety Digest 1/2008, Case 10, a feeder ship was making fast a tug aft. The tug suddenly moved off station, the messenger line ran off the winch drum end, and a seaman stepping in to clear a riding turn caught his ankle in the heaving line. He was dragged through the panama fairlead into the river and survived with bruising and a lost fingertip. The MAIB lessons: keep a sharp knife at every mooring station, never stand in the bight of a line, expect tugs to lose position in the ship's wash, and agree clear communications between ship and tug.

Common Mistakes

• Signing an agreement you have not read. You are entitled to review it and take advice first.
• Treating rest records as paperwork. They protect you and the ship, and false records undermine both.
• Standing in the bight of a mooring line or near a drum end under load.
• Assuming life on all ships is the same. A ferry and a bulk carrier are different careers.
• Neglecting your own welfare on long trips: sleep, exercise, contact with home.

Summary

• Life varies greatly by ship type: ferries and offshore mean regular home time; deep sea means longer trips and remote ports.
• Officers usually keep four-on, eight-off watches: the Second Officer the 12 to 4, the Chief Officer the 4 to 8, the Third Officer the 8 to 12.
• MLC rest rules: 10 hours in 24 and 77 in 7 days, in at most two periods, one of at least 6 hours, with no more than 14 hours between rest periods.
• The MLC guarantees a signed employment agreement, at least 2.5 days' paid leave per month, free repatriation within 12 months, a decent cabin, food and medical care.
• The route to Master runs through OOW and Chief Mate, with watchkeeping service at each step.
• COSWP (2026 edition) is the safety manual for working on deck.

Check Your Understanding

1. Which watch does the Chief Officer usually keep, and why?

Answer: The 4 to 8, so they are free to manage the deck department and cargo during the working day, and are on the bridge for twilight star sights.

1. What are the MLC minimum hours of rest?

Answer: 10 hours in any 24-hour period and 77 hours in any 7 days, in no more than two periods, one at least 6 hours long, with no more than 14 hours between rest periods (MLC Standard A2.3).

1. What is the minimum paid annual leave under the MLC?

Answer: 2.5 calendar days per month of employment (MLC Standard A2.4).

1. Name three situations that give a seafarer the right to repatriation at the shipowner's expense.

Answer: The employment agreement expires abroad; it is terminated by the shipowner or by the seafarer for justified reasons; the seafarer can no longer carry out their duties, for example through illness. Also, the maximum service period must be under 12 months.

1. Can the master make you work during your rest period?

Answer: Yes, for the immediate safety of the ship, people or cargo, or to assist others in distress, but you must be given adequate rest as soon as practicable afterwards. Drills should be arranged to minimise disturbance of rest.

1. What minimum size must a seafarer's berth be under the MLC?

Answer: At least 198 cm by 80 cm.

1. How much sea service does a UK cadet need before OOW certification?

Answer: At least 12 months of approved sea service documented in a Training Record Book, including 6 months on bridge watchkeeping duties (MSN 1856).

1. What did the MAIB recommend after a seaman was dragged through a panama fairlead?

Answer: Keep a sharp knife at every mooring station rather than relying on the bosun, prepare for tugs moving off station, define tug crew responsibilities and keep clear communication between ship and tug.

Sources

• International Labour Organization, Maritime Labour Convention 2006, as amended (Regulations 1.1, 2.1, 2.3, 2.4, 2.5, 3.1, 3.2 and 4.1).
• MCA, MSN 1856 (M) Amendment 1: UK Requirements for Master and Deck Officers.
• MCA, MGN 315 (M): Keeping a Safe Navigational Watch on Merchant Vessels.
• MCA, MIN 688 (M) Amendment 5: Code of Safe Working Practices for Merchant Seafarers, 2026 Edition.
• MAIB, Safety Digest 1/2008 (Case 10). This digest is from 2008; the lessons on mooring safety remain current.