Rest hours and shipping

Rest hours are a key issue when considering the working environment. Lack of rest can have consequences for safety on board and for individual well-being, health and general quality of life.



The whole area of rest hours is regulated by legislation and agreements. Various things need to be taken into consideration and this often gives rise to discussions on board and in the company. Another factor is that there are often traditions about how work is organized and rest hours on board, and then there are external factors that can make it difficult to comply with rest hour rules. There is a general lack of knowledge about the specific content of the rules and the consequences of failure to comply.

Discuss on board

In the guidance on shipping and rest hours, you can read how company and ship's management and individual crew can do something about rest hours. This requires everybody to adopt a new way of thinking; company management for organization, ship's management when planning watches and changing systems and routines - and that this is all done in dialogue with the crew.

Change is often difficult but if you involve personnel, it boosts their commitment. Greater insight and a feeling of having been involved in decision-making make it easier to accept ownership of changes. The extent of changes must be broadly agreed with the involvement of the entire crew. This could be done for example by calling an extraordinary safety committee meeting with everybody invited. This procedure creates the best basis for getting your message accepted.

Talk about it on board and discuss the best way of planning rest hours for everyone's benefit.


We do not know how many accidents are due to lack of sleep. Accidents seldom have a single cause. But lack of sleep plays a part in accidents because it leads to poor concentration and slower reaction times. It increases the risk of mistakes and people react slower which can mean not averting an accident in time.





Sleep is just like hunger and thirst. The longer we go without drinking, the thirstier we become. It is the same with sleep. We are normally awake for 16-18 hours, and then we get sleepy and can easily fall asleep. After sleeping for 6-8 hours, we awake well rested and can again function well for 16-18 hours.








The watch system provides the framework for how much rest individual crew get. At sea, there are two special watch systems: a 2-shift watch where there are two watches to share the working hours of the day and a 3-shift watch where there are three watches to share the day. The company makes the final decision about crew size based on the minimum manning laid down by the Maritime Authority – and thus also which watch system is used on board. By focusing on watch schedules, duties and how they are distributed, it is possible to try and create better opportunities for the crew to get sufficient sleep.




Port stays are one of the situations that give major challenges. There are many extra duties that require extra hands. Many ships have completely dropped port stay planning because they cannot get their plans to work. But taking a fresh look can provide good opportunities to plan things differently. First, you should plan as much rest as possible before arrival so that the crew are as rested as possible and have the energy for their duties.






After leave, people are normally in their normal daily rhythm. If you are starting your tour with night watches, it is a good idea to take the top off your need for sleep by being as rested as possible before going aboard. Let's say that you get up at about 06.00 - 07.00 hrs. This means that by 18.00 -19.00 hours, you will have been awake for 12 - 13 hours. So it is possible to sleep for a few hours before starting work at midnight. Your body clock will still mean that you feel very tired at 03.00 - 04.00 hours but it will be less pronounced. Your accumulated sleep deficit will be those few hours less than if you had not slept at around 18.00 - 19.00.


Research has shown a marked increase in digestion problems for people who work changing watches. After sleep problems, stomach problems are the most pronounced consequences of changing working hours. There may for example be a tendency to constipation or diarrhoea and the explanation may be that changing watches means irregular mealtimes. This may lead to eating more snacks with too much fat and carbohydrate.





The company is responsible for actual route planning and manning. And it is they who set the overall framework for planning hours of work and rest.




This guidance also aims to give some answers and to inspire a fresh look at work planning so as to make it possible to ensure more people get the rest they need.

>> Download a brief introduction to the guidance

>> Order the guidance at SEAHEALTH webshop

In the wake of the questionnaire survey, Seahealth has issued guidance on rest hours.

>> Read a summary of the guidance

International Regulation

Information can be obtained in MOSH Guidelines 6.7.6. Fatigue.


Useful link:

IMO: Guidelines on Fatigue - MSC/Circ.1014 Guidance on Fatigue Mitigation and Management