The spectrum of illnesses on board a ship is broad and dependent on the crew and passengers. As well as sea sickness, various other health problems occur. The most common causes of medical consultation are respiratory illnesses amongst the passengers, skin diseases amongst the crew and injuries. Passengers tend to injure themselves on land and the crew on board.

Cardiovascular illnesses are common amongst passengers. Dental treatment is often necessary, especially amongst the crew, and involve treatment by a dentist in the next port more often than other illnesses. 

The tasks of a permanent ship's doctor include general, emergency and preventative medical care as well as monitoring kitchen and accommodation hygiene, conducting immunisations and implementing measures to prevent infections and epidemics on board. The job profile also features aspects of tropical medicine. Responsibility for medical supplies and care and maintenance of them is also the responsibility of the ship's doctor.

In the navy, the ship's doctor is also given responsibility for conducting medical training for the crew. In the civilian sector, periodic first aid and resuscitation courses as well as safety exercises for the crew are also amongst the ship's doctor's tasks.

The professional and human requirements of ships' doctors are high and vary considerably from ship to ship. In Germany, ships' doctors' qualifications are stipulated by law. As well as knowledge of surgery and internal medicine, ship hygiene, travel and tropical medicine and basic knowledge of dentistry, ophthalmology and other "small subjects", a large amount of personal responsibility is the main requirement. Given the corresponding equipment, knowledge of sonography and expertise in radiation protection are necessary. As well as professional experience, ships' doctors must have a fitness for sea service examination certificate, language skills and act in a level-headed manner during emergencies. Ships' doctors are usually assigned an officer rank and are directly subordinate to the captain, who is authorised to instruct them. The form of the contract and the workplace at sea can be very different depending on the shipping company. Before signing a contract, doctors should seek precise information regarding remuneration and payment, the quality of the equipment on board, the area of responsibility and in particular questions regarding professional liability insurance (in: Schlaich C. et al. Schiffsärzte auf Passagierschiffen. 2010;17(4):174-1792)