PSSR-L3.2

Fatigue, hours of rest, alcohol and drugs

PSSR-M3 · People on board · PSSR-M3-A Communication, fitness for duty, the 2026 harassment competence, and looking after yourself and others.

Fitness for duty comes down to **sleep, rest records and sobriety**. The law sets minimums for all three.

Where this sits

Governing: MSN 1877 (M) Amendment 1 (MLC Hours of Work Regulations 2018); MGN 505 (M) Amendment 1; MGN 590 (M+F); Railways and Transport Safety Act 2003, ss.78 and 81; COSWP 3.6. Builds on: L3.1.

Fatigue

COSWP 3.6.1 quotes the IMO definition (MSC/Circ.813): fatigue is "a reduction in physical and/or mental capability as the result of physical, mental or emotional exertion which may impair nearly all physical abilities including: strength; speed; reaction time; coordination; decision making; or balance." Tired crew fall off things, miss hazards and make bad calls on the helm.

The company and master should organise work to limit fatigue, but you have a duty too (3.6.3-3.6.4):

  • arrive on board rested;
  • take your scheduled rest and aim for about eight hours' sleep in 24;
  • eat properly and lightly before sleep; avoid alcohol and caffeine before bed;
  • put screens away before sleeping;
  • record your hours of rest accurately.

Hours of rest (MSN 1877)

MSN 1877 applies the MLC hours of work regulations and states that charter yachts are covered (2.3).

Rule Minimum
Rest in any 24-hour period 10 hours
Rest in any 7-day period 77 hours
Daily rest split No more than two periods, one at least 6 hours
Interval between rest periods No more than 14 hours

Worked check: rest 2300 to 0700 (8 h) and 1300 to 1500 (2 h) gives 10 hours in two periods, the longer being 8 hours. The longest gap between rest is 0700 to 1300 (6 h) or 1500 to 2300 (8 h), so all within 14. Compliant.

Other points:

  • Short breaks are not rest (4.2).
  • A call-out during rest earns compensatory rest (4.1).
  • In an emergency, the master may suspend the schedule, then must give adequate rest (7.1).
  • A table of duties is posted in an accessible place (6).
  • Records are kept for each seafarer, completed at least monthly in arrears, endorsed by the master and the seafarer, and kept for at least one year (8).

WARNING: Honest records Falsified rest records hide exactly the fatigue that causes accidents, and they expose you as well as the yacht. Record what you actually worked.

Alcohol

Under STCW regulation VIII/1 the limit is 0.05% blood alcohol or 0.25 mg/l in breath. The UK aligned its law in 2015 (MGN 590):

Medium STCW UK (RTSA 2003 s.81)
Blood 0.05% 50 mg per 100 ml
Breath 0.25 mg/l 25 micrograms per 100 ml
Urine none 67 mg per 100 ml

Under s.78, a professional master, pilot or seaman on duty commits an offence if their ability is impaired by drink or drugs, or if they are over the limit. MGN 590 also says it is an offence to be impaired at any time on board if you might be required for emergency duties. It recommends company policies banning alcohol for four hours before a watch. Most yachts go further, with zero-tolerance rules during charter or under way.

Drugs and medication

Recreational drugs are a sacking offence on almost every yacht and a criminal matter in many ports. Tell the responsible officer about prescribed medication that could affect alertness (COSWP 3.4), and check before mixing medication with alcohol.

Practice questions

5 questions

recall · core

What is the minimum rest required in any 7-day period under MSN 1877? (a) 84 hours (b) 77 hours (c) 72 hours (d) 70 hours

recall · core

What is the UK prescribed breath alcohol limit for professional seafarers? (a) 80 micrograms per 100 ml of breath (b) 35 micrograms per 100 ml of breath (c) 25 micrograms per 100 ml of breath (d) 50 micrograms per 100 ml of breath

recall · core

How long must endorsed hours-of-rest records be retained? (a) Five years (b) Until the next flag inspection (c) Three months (d) At least one year

recall · core

Into how many periods may the 10 hours of daily rest normally be divided? (a) No more than two, one of at least 6 hours (b) It must be one continuous period (c) No more than three, each at least 3 hours (d) Any number, if the total is 10 hours

scenario · core

On a busy charter day your last rest ended at 0700. With only short breaks you worked until 0100, and the bosun wants you back on deck at 0600. What is the position? (a) No breach, because short breaks count as rest (b) No breach, because charter yachts are exempt from MSN 1877 (c) No breach until the 7-day total drops below 77 hours (d) The limits are already breached: 18 hours passed between rest periods and you had only 5 hours of rest in the 24 hours from 0700; tell your head of department, record the hours honestly and expect compensatory rest

Independent study. xplor is not an accredited training provider and awards no certificate or Certificate of Competency. The PSSR Certificate of Proficiency can only be issued after an MCA-approved (or other recognised) course, and the MGN 718 top-up must be completed on the MCA-designated module. AI-drafted content pending subject-matter-expert review.