Working periods should not be extended or prolonged to an extent that health and safety is compromised. It should be remembered that accidents are more likely when personnel work long hours because their concentration and efficiency deteriorate and their safety awareness is reduced.

When breaks are taken in the course of a diving operation, the diving contractor will need to ensure that the health and safety is not compromised in any way and that qualified and experienced personnel are available to act as reliefs during these breaks. This is particularly important in relation to supervisors whose responsibilities are often onerous and stressful. Any such handovers of responsibility should be recorded in writing in the operations log.