The public image of the maritime physician is one of a physician practising on board a ship.  Indeed, it is difficult for a physician to understand and be knowledgeable about maritime medicine without having working experience on board.  Practising as a maritime physician on board is, first of all, living the life of a sailor which means sharing long days at sea with the crew and looking forward to enjoying stops at ports.  The position of a maritime physician on board has often been disparaged.  In the past, it was either used as a commercial advertisement (In the XIX century, a British liner company advertised that there was a milk cow and a physician on board!) or it was thought of as an easy job since it was widely believed that crew members were generally in good health and, consequently, the maritime physician did not have much work to do.  These are, of course, stereotypes from another time.  Being a physician on board means being an all-round physician with a strong knowledge of emergency medicine, surgery, dermatology, and general practice.  The maritime physician on board must be prepared to face any medical or surgical event.  In emergency situations, when an evacuation is required, he must be able to stabilize patients’ health status until the evacuation is possible and prepare the patient for the evacuation, most often by helicopter.  Being a physician on board seems to be an exciting job but few posts are available.  Indeed, positions for maritime physicians practising on board are (mostly) found on passenger ships such as liners and ferries, which may carry large crews and thousands of passengers (see also chapter 9).  These ships have medical teams with one or several physicians, sometimes including a surgeon, and nurses.  The medical facilities on board are similar to small hospital wards with outpatient and in-patient facilities, intensive care and surgical wards, and biomedical laboratories.  Given the large number of passengers of all ages and the physical conditions on board, the physician must be prepared to deal with any kind of pathology, in particular cardio-vascular or infectious diseases.  Indeed, the confinement of thousands of tourists in a restricted space like a ship (even a large ship) increases the risk of epidemics (especially gastro-enteritis, commonly due to norovirus).  The maritime physician plays a leading role in managing such outbreaks and in communicating with port health authorities.   

The medical management of crew and passengers during the time spent in ports is also an important aspect of maritime medicine.  It requires a good knowledge of tropical diseases such as malaria, dengue fever, as well as tropical maritime risks, for instance ciguatera toxicity from fish and bites or stings from marine animals.

The other types of ships with maritime physicians on board are large military ships (ranging from frigates to aircraft carriers) and civil ships such as oceanography ships and cable layers.   On board military (combat) ships, the physician is essential because of the frequency of casualties (traumas, burns and toxic effects).  Admiral Nelson once said: “during military operations, health is the most important thing”.  On board civilian ships like oceanography ships, the population is made of professionals (scientists, technicians) whose status differs from that of sailors.  These professionals are exposed to the risks associated with living on board and to the risks associated with their specific professional activities (e.g. working in immersion for scientific exploration (small submarine), operating Remote Operated Vehicle or sounding lines, working in a laboratory on board). 

The ILO, Maritime Labour Convention, 2006 (MLC) (Standard 4-1 4(b)) makes it mandatory to have a physician on board when the total number of persons (crew and passengers) is over 100 and the ship is engaged in international voyages of more than 3 days.  According to these regulations, it is not mandatory to have a physician on board a ship like an oceanography ship, which carries 80 to 90 people and navigates for more than 15 days and sometimes for 30 days far away from a port.  This international requirement can be criticised as the health risks is greater on board such ships than on board ships that are only at sea for a few days.   An additional requirement to have a physician on board when the ship carries over 50 people and is at sea for longer than 15 days would be beneficial.

The maritime physician on board does not merely wait for medical or surgical emergencies.  He watches over the health of personnel at all times during the course of the voyage.  He has to take charge of all health problems ranging from ear, nose and throat problems or allergies due to air conditioning to psychological or psychiatric problems. In a restricted environment such as a ship, he becomes everyone’s confidante.  In addition to medical care, he is also in charge of carrying out administrative tasks such as the management of medical equipment.  He is often the hygiene expert on board with oversight of insect and rodent control, disinfection and ensuring the quality of water and food, including nutritional balance of every meal.  Finally, he is the advisor to the commander of the ship who is often his direct administrative supervisor.

Whether there is a physician on board the ship or not, every seafarer must be assessed for medical fitness at sea before boarding, this assessment is done by maritime physicians who have appropriate competencies in occupational health.  In accordance with the MLC (Regulation A1-2), in each country, physicians must be authorised to issue certificates of fitness by a competent national authority.  These physicians may practice within specialised services such as the “seafarer’s health services” in Spain and France. Alternatively they may be drawn from occupational physicians and primary care doctors who have appropriate skills and experience. Ideally, maritime physicians, before practising “on the ground”, should have working experience on board.  This will ensure a full understanding of all health constraints associated with work at sea.  Seafarers’ health services may, as in France and Spain, be organized like onshore occupational medical services, with responsibilities for hygiene, sanitation, safety and working conditions on board.  Standards for compliance for most of these topics are the subject of statutory control measures. 

Occupational health on board is another domain of activity of the maritime physician.  In this, the maritime physician must study and understand the impact of living and working on board on sailors’ health in order to prevent the occurrence of health problems.  This includes all questions related to seafarers’ medical fitness at sea, the exposure to the physical nuisances on board ships (noise, vibrations), stress and addictions because of the particular psychological environment on board, toxicological problems, postural problems (Musculo Skeletal Disorders), work related accidents, hygiene, sanitation and, finally, dealing with national and international regulations.   For many of these topics the physician will need to seek advice from or call on the expertise of other disciplines to secure good risk management.

Maritime occupational health practice is concerned with all categories of professional seafarers e.g. merchant seafarers, fishing, offshore activities, and professional divers.  The maritime occupational health physician must therefore be knowledgeable about all aspects of maritime occupational risk.  He or she needs to have in-depth knowledge about physical nuisances (noise, vibrations, temperature and lighting), psychological issues (such as stress related to work and to the environment) and organizational issues.  Like occupational health physicians in charge of companies ashore, their goal is to improve seafarers’ living and working conditions on board, and to study health problems that are specific to working at sea or that may interfere with such work.

In addition, the maritime occupational health physician is in charge of assessing individual seafarers’ medical suitability for their tasks and duties, both routine and emergency. The obligation to assess a seafarer’s suitability for their work at sea was consolidated with other requirements in the MLC, having been a feature of earlier ILO Conventions. Individual assessment is important because of the hostility of the maritime environment and the great distance to any health facility when at sea.  In addition to assessing the seafarer’s ability to meet the requirements of their post (mechanic, cook, helmsman…), the maritime physician also has to assess the risks caused by the seafarer’s health status and decide if the risk is acceptable or not. This is a major responsibility as the safety of the ship and all its crew may depend on it.

The maritime physician should also carefully assess any individual susceptibility to health risks associated with exposure to noise, vibrations and air conditioning.  On board, sailors are exposed to these nuisances 24 hours a day for several months per year.  The physician also needs to pay great attention to any individual stress factors that could be made worse by the psychological environment on the ship.

Maritime occupational health risks may also arise from activities carried out when the ship is in port, for instance the risks from entry to enclosed spaces during cargo handling and cleaning operations.  Many accidental exposures to risk occur when the ship has berthed, during maintenance and repair work (see also chapter 16).  Maintenance interventions on cooling systems (cold store/ refrigeration, air conditioning, fire prevention systems) are particularly dangerous as there may be leaks of cooling fluids such as Freons or ammonia and these have lead to deaths that are attributable to their effects at sea as well as in port.  During loading and unloading operations workers are also exposed to traumatic or toxicological risks.  During cleaning operations of hydrocarbons tanks, detailed protocols to ensure safe working practices are needed to prevent intoxication with dangerous gas, especially carbon monoxide. Because these toxic risks are frequent, the maritime physician needs have an in-depth knowledge about toxicology.

Maritime health experts from a wide range of scientific disciplines may also be engaged in “littoral environmental medicine” a subject that is becoming increasingly important.  It includes the control of pollution caused by ships on the littoral environment.  Polluting agents include hydrocarbons (black tides), agro-industry products (soya dust), fish and shellfish pollutants, or microorganisms (algae, bacteria and viruses) transported by the water from ballast tanks.  There are many examples of such pollution. For example, in Barcelona Spain, asthma epidemics occurred due to soya dust released during ship unloading, in Japan, intoxication of the population occurred through the consumption of fish contaminated by mercury (Minamata disease), while in South America a cholera epidemic following the dispersion of contaminated water from the ballast tank. Toxic agents e.g. bromomethane, used as a fumigant, or infectious agents (vectors infected with malaria or viruses) can be transported in shipping containers, posing a risk wherever the container is opened.  This is a real challenge given the huge increase worldwide of maritime transportation.

The third type of maritime physician is the maritime emergency specialist.   During the last decades, most developed countries have set up centres for maritime radio-medical consultations (Chapter 8).  These centres are open 24 hours a day and their task is to assist ship captains with the management of crewmembers’ health problems.  During the last 15 years, since the IMO Convention STCW 95 was agreed, two developments occurred simultaneously: on the one hand medical knowledge has improved among crew members since officers on merchant ships were required to be competent to carry out simple medical procedures such as intra muscular injections.  At the same time communications between ships and onshore advisers have vastly improved with the development of maritime satellites and the internet.  This is allowing the development of more advanced telemedicine systems, although these are still at an early stage.  With telemedicine systems, physicians in radio-medical centres can already receive patients’ data such as ECGs and photographs directly and almost in real time and two-way interactive video is now becoming practical as more satellite bandwidth is made available.     These enable better diagnosis and patient management and this enables better advice to be given on management of ill or injured seafarers. With improvements in telemedicine, medical maritime physicians are beginning to be able to practice general medicine from a distance as opposed to merely being in charge of emergency situations.

When there is a physician on board, telemedicine remains very useful.  While caring for a patient, the physician on board is able to discuss diagnosis and treatment with colleagues from the radio-medical centre.  This greatly reduces the sense of isolation that many physicians at sea experience.

When a medical or traumatic situation requires a medical evacuation and the ship is near rapid and adequate means of evacuation, maritime emergency physicians take charge in collaboration with search and rescue services.  Emergency physicians may be transferred on board the ship, usually by helicopter, so that they can prepare the wounded or sick patient for evacuation.  Such interventions are difficult, both physically and technically, because conditions at sea can be erratic.  Emergency physicians working in the maritime sector must have, aside from a strong background in emergency medicine, an in-depth knowledge about treatment under special conditions in the air (altitude, pressure, vibration and restricted space) and living conditions on board.   The emergency physician may sometimes also be in charge of diving accidents and leisure water sports accidents.

The three types of maritime medical practice: assessment of fitness, management of medical emergencies, and healthcare on board and in port, have little in common.  Yet, the nature of maritime medicine is such that, no matter what is the type of practice, maritime physicians must have an in depth understanding of the maritime environment, its laws and regulations. They must understand sailors’ living and working conditions on board, the special psychological conditions sailors are exposed to, as well as all the other risks at sea (immersion, hypothermia etc, see chapter 22).   Maritime health is not a single medical specialty. It is a medical field with several specialties, all of which are concerned with the sea; a very hostile environment. The medical contribution to maritime health almost always involves working with other professions who have equally well developed complementary skills that enable problems to be defined and resolved. Medical specialists need to understand the global nature of the maritime sector and work in collaboration with seafarers and health professionals across the world. Many of the regulatory requirements in place are common to all maritime nations as they are derived from agreed international conventions. However the details of their implementation can vary from country to country.