Although prevention of incidents leading to evacuations at sea is of vital importance, little is known about its causal patterns and demographic determinants. We investigated therefore relationships between age, occupation and nationality and causes of evacuations. The data were obtained from the Telemedical Assistance Service (TMAS) in Denmark between 2004 and 2014 supplemented with data on all seafarers from the Danish Maritime Authority (N = 73,344). These data included information on broad age groups, occupational position and nationality. The outcomes were evacuations from any cause and in four broad categories of causes leading to evacuations. A total of 403 evacuations were reported in the 11-year study period. 27% of the evacuations were due to external causes, 19% due to diseases of the circulatory system, 14% due diseases of the digestive system and 40% from other or undetermined causes. Age-adjusted all-cause evacuation rates varied between 1.4 and 3.4 incidents per 1000 person-years in 2004–2014 for officers and between 3.3 and 20.2 incidents for non-officers. An elevated risk of evacuations was found among both officers and non-officers aged ≥50 years, compared with those aged 30–49 years with odds ratios of 2.73 (95% confidence intervals 1.66, 4.50) and 2.59 (2.03, 3.31), respectively. The odds ratios for non-officers from non-Danish European Union and from non-European Union countries compared with Danish non-officers were 1.51 (1.12, 2.04) and 0.55 (0.42, 0.71), respectively. In conclusion, working as non-officer, older age and non-Danish EU nationality were associated with a higher risk of evacuations irrespective of the cause leading to evacuation.