Objectives While life at sea traditionally has presented a variety of potential hazards, rigorous measures have been taken in the past decades to ensure the safety and health of all aboard merchant ships. The aim of this study was to examine overall and cause-specific mortality among Danish seafarers in light of these changes.

Methods A cohort of 44 555 male (75%) and female (25%) seafarers employed on Danish ships during 1986–1999 was established through records from the Danish Seafarer Registry. Subsequently, information on vital status and causes of death was linked to members of the cohort from the Danish Civil Registration System and the Danish Register of Causes of Death using unique personal identification numbers. Standardized mortality ratios (SMRs) were calculated for the seafarers using rates from a sample of the Danish employed population.

Results Among seafarers with first employment prior to 1992, the overall mortality was high, with increases observed for many individual causes of death (overall SMR 1.78, 95% CI 1.72 to 1.83 for male seafarers; SMR 1.61, 95% CI 1.48 to 1.75 for female seafarers). Mortality among seafarers employed in the following period was reduced, with only a slight remaining excess of deaths. This excess in mortality was evident primarily among non-officers on board tankers and smaller ships.

Conclusions During recent decades, mortality among seafarers has changed, replacing the traditional image of a high-risk profession with almost normalised figures compared with the general working population. Marked imbalances in mortality according to job and ship categories have persisted though.