Morbidity among the personnel of a Kola-based (beyond the Arctic circle) atomic (ASM) and diesel-powered (DSM) submarines in the course of long-distance cruises in different waters of the world ocean was studied. Statistics was collected from the reports of submarine medical officers since 1969. Levels and causes of morbidity were analyzed. According to the data of many years' observations, within the structure of primary diseases of military contractors on cruises the leading place has been occupied by respiratory disorders followed by skin and subcutaneous fat problems, and digestive diseases. Incidence of chronic diseases among ASM and DSM personnel was evaluated. The authors raise the issue of dental care quality provided to submariners.