The current scope of maritime medicine


Maritime medicine (also called maritime health and nautical medicine/health) covers a large number of themes including:

  • the environment of seafaring( effects of microclimate and macroclimate, noise and vibration aboard ship on seafarers, other work related exposures);
  • conditions of work and life on merchant, passenger and fishing ships and on oil rigs;
  • sanitary problems on ships;
  • nutrition and food hygiene aboard ship;
  • pathology of workers employed on ships (diseases, accidents and injuries);
  • toxicology of seafaring;
  • exotic diseases;
  • health problems of navy personnel;
  • personal hygiene of seafarers;
  • vaccinations of ship’s crew members and other preventive interventions
  • seafarer’s health education;
  • training of seafarers to provide basic medical services on board;
  • health standards for work at sea and medical examinations of seafarers;
  • radio medical advice for ships. 

Diving and underwater medicine problems are sometimes included, although this field has separately developed and a number of centres around the world employ and train specialists in this area. They care not only for professional but also for recreational divers and they treat not only decompression sickness but also other cases of accidents and diseases. The risks in shipbuilding and dock work also have features that are shared with maritime medicine and so may be considered to be a part of its practice.

The practice of maritime medicine is supported by:

  • special training for those who provide healthcare to seafarers. This includes international postgraduate training courses in maritime occupational health for doctors;
  • Academic and research institutes in a some of the major maritime nations;
  • Journals on maritime medicine or health from a number of countries;
  • The activities on the International Maritime Health Association;
  • Two yearly International Symposia on Maritime Health.
  • WHO designated collaborating centres in maritime occupational medicine.

Maritime medicine has important areas of shared interest and competence with occupational medicine, primary health care, emergency medicine, public health, tropical medicine, and travel medicine. 

Current practice forms the subject matter for this book, but how did it arise?




Man has been going to sea since before recorded history and so the health problems of seafaring: disease, injuries and transmission of infections have long been present. The increased volume of sea traffic and longer voyages during late medieval times in Europe led to some of the first legal instruments concerned with maritime health. These included quarantine requirements, especially around the Mediterranean Sea, that were aimed at preventing the introduction of diseases such as plague and cholera into port cities.[1] Laws on the care of ill and injured seafarers in foreign ports that placed duties and costs on the ship captain were also in place in the codes of some Spanish, French and Italian jurisdictions.[2]

The need to care for those ill or injured on board resulted in the carriage of medicine chests and, on some of the larger ships, to a surgeon as a crewmember. Where this was not adopted medical guides were available that gave practical information to ship masters on the prevention, diagnosis and treatment of illness and injury using the items included in the medicine chest.[3]

Most of the largest ships with the biggest crews from the 1500s onwards were warships. These made long voyages, especially those from the navies of Spain, Portugal, Netherlands and Britain, all of whom had distant colonies, some located in tropical areas where the crews encountered new diseases such as malaria and yellow fever that could cause a major toll of casualties. These navies were involved in repeated battles with one another leading to large numbers of serious injuries in a short period. Close and poorly ventilated living conditions (one hammock every 40cms) helped the spread infections and a diet based on salt meat and dry cereal and pulses resulted in deficiency diseases.

Naval medicine was recognized as essential for an efficient navy and this led to routine engagement of surgeons to serve aboard.[4] These were among the earliest doctors to be required to have passed specific examinations.[5] They were concerned with the fitness of new seafarers, who were often either convicts or those coerced into service by violence.   They also dealt with ship hygiene, although this depended as much on the attitudes of senior officers; they treated day-to-day illness and injury and worked heroically to deal with battle casualties and major outbreaks of infections. Occasionally ship surgeons made major contributions to disease prevention, for instance the studies of James Lind on the use of lemons to prevent and treat scurvy.[6]

Navies established hospitals ashore or contracted for hospital care both to ensure that seamen could return to their duties rapidly and also that they did not abscond before the time came for signing off at the end of a period of service.[7]

A few of the merchant ships undertaking long voyages also made comparable arrangements for the provision of ship surgeons. The ships of Netherlands, Britain and other countries sailing to the Far East (East Indiamen) did so, as did whaling ships.[8] The latter were required to carry a surgeon.[9] From the end of the eighteenth century Britain, by then economically dominant in merchant shipping, required ships engaged in the slave trade, those carrying convicts sentenced to transportation, some emigrant ships and troopships to carry surgeons, who were responsible for maintaining a log of death, illness and injury aboard and could be held accountable for it at the end of a voyage.[10]

Coastal shipping in Europe had no specific arrangements for maritime health and it appears that ships in other parts of the world also did not.

In the first half of the nineteenth century the first steam ships started operating, creating very different conditions of work and risks that those found on sailing vessels. Maritime trade also increased ever more rapidly. As a consequence the loss of life at sea became a politically important topic in a number of countries.[11] This was attributed to unseaworthy or overloaded ships by many commentators, who also saw the spreading of risk by the use of insurance as a means by which owners could escape the financial loss from wrecked ships and cargoes that failed to be delivered. In part to offset these allegations ship owners pointed out that many crewmembers were unseaworthy, either because of a lack of training and experience or because of health problems, especially self inflicted ones from alcohol or venereal infections. This debate led to action first by individuals and voluntary groups and then eventually by governments, who often had to confront the ship owners – the very group who had fostered parts of this debate – with the unpalatable need to spend money on training, crew numbers, disease prevention and medical care. 

This process is well seen in the development of the 1867 Merchant Shipping Act in Britain.[12] A hospital for merchant seaman hospital had been established in Greenwich by voluntary effort in 1821 and a series of articles published in early 1867 pointed to the patterns of disease in different groups of seamen seen at the hospital.[13] A voluntary committee with prestigious members set itself the task of investigating the condition of health and welfare of merchant seamen and its recommendations played an important part in shaping the Act.[14] These included: better specification of the medicine chest contents, a requirement for every ship to carry an approved medical guide, quality assurance for lemon juice provided to prevent scurvy and arrangements for masters to request a medical examination of a seaman before embarkation. Medical standards were given and the examination had to be performed by a doctor approved by the marine department. Thus a fairly comprehensive framework for maritime medicine was put into place. Weaknesses included the lack of action on diet (other than antiscorbutics) and on the quality of accommodation. Both had been recommendations the voluntary committee but were opposed by ship owners because of costs. The optional nature of the provisions for medical examinations meant that they were little used.[15] However all these aspects were further investigated in the years that followed. 

The casual employment of seamen meant that they were prey to abuse between voyages. Ports developed a ‘sailortown’ where seafarers were relieved of their pay with the aide of alcohol and prostitutes and could even be kidnapped and find themselves aboard a new ship before the effects of alcohol had worn off.[16] Concern about this situation and especially the moral overlays of prostitution and the spread of venereal disease led to charities setting up missions in port areas to provide friendship, economic food and accommodation, usually accompanied by a religious message of salvation.[17] This mission work formed the core of today’s seafarer welfare provisions. 

Real impetus to improved maritime health was given first by the acceptance of the germ theory of infection and the rational preventative measures that followed from this in the period 1870-90. This was followed in the next thirty years by further improvements from the understanding of the role of arthropod vectors in diseases such as yellow fever, malaria and typhus and their control.[18] Vaccination had long been used to prevent smallpox but the early years of the 20th century saw the development of immunization against diseases such as typhoid. Infections had been the leading cause of seafarer deaths from illness in the nineteenth century and these rapidly became less dominant. 

Other important improvements included the better diet made possible by the use of refrigeration and canning, the start of radiomedical advice services and the introduction of training for officers in medical care. The provision of an onboard sick bay enabled treatment to be provided in a better setting than the crowded crew accommodation. 

Arrangements for maritime health were largely national responsibilities until the 1920s, with the exception of those concerned with transmission of serious infectious disease. The creation of international bodies such as the International Labour Office (ILO) and the League of Nations after the First World War placed the health and welfare of seafarers in the international arena. In addition fast growing maritime nations such as Norway, which lacked the networks of longer established nations in international maritime trade sought to create the first truly international provisions. Early work by the ILO on protection of young seafarers and by several bodies on venereal disease was consolidated in a series of Red Cross conferences, the first of which was held in Norway in 1926.[19] These were discussing what could be seen as the modern agenda for international maritime health, as identified at the start of this chapter, for the first time. Like earlier national initiatives many of the more difficult or costly issues about working and living conditions were put to one side, but progress was made on collaboration to provide the recently available treatments for syphilis in most ports and to develop approaches to the prevention and management of tuberculosis, now seen as one of the major health risks in seafaring. Effort was also directed at the provision of welfare facilities in ports.

The two world wars of the twentieth century gave rise to a number of improvements in maritime health, largely because of the need to maximize the use of the available pool of seafarers as well as to deal with the consequences of enemy action at sea. Survival at sea was subject to detailed investigation and improved equipment and practices followed; infectious diseases from the venereal to the malarial were subject to rigorous control regimes – for the former for the first time free from moral overlays. Accommodation was improve, perhaps surprisingly on war built merchant ships – largely because of the United States liberty ship building programme.

 Recent changes


There have been important changes during the last half century that affect the health and work safety of ships’ crews:

-         the globalization of the shipping industry,

-         automatization and mechanization of work on ships, with the transport of cargo in containers,

-         progress in navigation techniques,

-         decrease in the number of crews on ships, lack of stability in the employment of seafarers on single short-term contracts, who often come from low cost labour supplying countries rather than being permanent employees of the company who come from the company’s and the ship’s state of origin.

-         reflagging of ships, multicultural crews on ships operated under flags of convenience.

The continuing medical challenges of injury and illness on board remained the same as before, but better communications has enabled telemedical advice to be readily obtained in all parts of the world’s oceans. The introduction of antibiotics and better antimalarials has further reduced the threat from infectious disease, although with a continuing race between new therapies and resistant organisms. Physical, chemical and biological health hazards as well as the ergonomic ones related to physical job demands and psychosocial ones from isolation, organization pressures and complex work demands remain or have increased because of reduced crews and tighter schedules. 

The standard of accommodation of crew members on board has improved, systems of communication with shore are better now, it is easy, if costly, to communicate with the family in the home country. There is less strenuous physical work to do during the voyage but this, coupled with ample but unhealthy food may lead to overweight and obesity of some seamen. 

The number of crews on ships has been drastically reduced, from about 40 on a cargo ship of medium size to about 24 or even less nowadays, and they have varied responsibilities, which increases the work related stress. On modern ships with small crews there are not many opportunities to meet other off duty seafarers onboard during the long oceanic voyage of the ship, to speak to them and to enjoy their company. Seafarers of several different nationalities are often employed on the same ship. This complicates social contacts between them, because of language barriers and cultural differences. All these factors affect the social wellbeing of many seafarers.

The technical progress in loading/unloading cargo in ports, and the use of containers very much shortened the time of stay of the ship in ports. This has limited the opportunities for seafarers to spend time on shore, to visit a dentist or a doctor in the foreign port during the voyage, to go to the cinema or have a drink in a bar there, to see places of interest. Security and visa restrictions make going ashore more complex or even impossible for some seafarers.

Service at sea may be more boring as well as more demanding and less secure now than it was few decades ago.


  Epidemiology of seafaring


Seafaring has always been considered a dangerous occupation. Crews of merchant ships are exposed to extremes of weather, hazards connected with the operation of mechanical equipment, toxic cargoes and toxic substances used aboard. Seamen are swept overboard by heavy seas, they die as a result of vessel casualties (foundering, capsizing, explosions, fires).

Their health is affected by noise, vibration, smoke inhalation, fatigue, overwork, and other exposures described in the chapters of this book.

Travel to the tropics results exposure to exotic diseases as malaria, and other infections.

In case of sudden illness or an accident and injury during the ship’s voyage, the chances of receiving proper and effective treatment are for seafarers not as good as for a worker on shore because of lack of direct and prompt access to qualified medical assistance. Seafaring is therefore a dangerous occupation with a higher morbidity and mortality than in most occupations ashore.

Statistical data on morbidity and mortality among seafarers have been regularly collected in maritime countries, analyzed and compared. There are, however, major problems in using such information to derive reliable estimates of the incidence and prevalence of disease because diagnostic criteria, if used, are inconsistent and it is almost impossible to derive a reliable population denominator for a mobile population whose employment is often causal and who alternate between periods at sea and ashore. Studies have been performed, mainly in Northern Europe, especially Scandinavia, where population registers can be used, and North America. Here the data are rather better than in the rest of the world. As a consequence there is very little information on the patterns of injury and illness in seafarers from the countries from which most are now recruited.

Naval epidemiology has not suffered from these problems, the population was known and all injuries and illnesses were recorded by naval surgeons. Detailed annual reports could be produced and these were used as the basis for assessment of risk and for determining the priorities for preventative programmes. An active and rational approach to the discipline of ship hygiene was derived from this high quality information.

The occupation of fish catching has been shown to be even more dangerous. Data on morbidity and mortality have also been published and some specific risks have been identified, such as the high incidence of limb injuries from entrapment by fishing gear and winches.. A number of studies indicate that they have the highest risks of all groups of workers.[20] Comparative studies of work-related mortality among fishermen in various countries indicates that it has recently been 25-30 times higher than in workers on shore; in the USA it was 8 times higher than in truck drivers, 16 times higher than in policemen, and 40 times higher than in general population of the country.[21]

Accident and injury rates for seafarers, are generally higher on on older rather than on newly constructed ships; on smaller than on large ships, and on general cargo than on tanker ships. This may reflect the nature of the work and the quality of safety management but it may also be a result of differential selection of best performing seafarers for certain classes of vessel.


 A global industry


The process of domestic deregulation and external liberalization of economies in many during the last two-three decades is termed globalization.

The liberalization of the labour market,including in the shipping industry, has weakened collective bargaining, minimum wages and safety at work.

Ship owners have been among the beneficiaries of globalization, they are now able to operate their ships at lower labour costs than before. But for seafarers in many countries, globalization has been a mixed blessing. They can now look for employment on ships operated under various flags. But for many of them, working conditions and safety as well as arrangements for healthcare have deteriorated.

On ships flying flags of industrialized countries, there is often job security for crews and their health care is fairly well organized. Seafarers are regularly examined by doctors, their medical expenses are fully covered by insurance, and strong trade unions protect their social security and wages.

But during the recent two decades, a large number of ships of industrialized countries have been re-flagged to ‘open registers’ and operate under so called “flags of convenience” (FOC), hence their crews lack this protection..

Seafarers of any nationality can be employed on such ships. A high proportion comes from developing countries with limited healthcare services or social security. Their contracts are usually for short periods of time, often for one or two voyages only.

Low registration fees, low or no taxes, and freedom to employ cheap labour are the motivating factors behind a ship owner’s decision to “flag out”.

FOC registers have poor safety and training standards. In many cases these registers are not even run from the country concerned. Once a ship is registered under a FOC, the ship owners can recruit the cheapest labour they can find, pay minimum wages and cut costs by lowering standards of living and working conditions for the crew. The home countries of the crew can do little to protect them because the rules that apply on board ships are often those of the country of registration. As a result, most FOC seafarers are not members of a trade union.

The international organizations such as ILO, WHO, IMO, and the ITF have done much to introduce legislation protecting the safety of work, health and wellbeing of international seafarers, fishermen and other maritime workers.

International collaboration and the sustained efforts of international organizations such as ITF and IMHA have contributed to the study of health problems of seafarers and the protection and promotion of their health. But much remains to be done.



[1] Booker J, Maritime Quarantine 1650-1900. Aldershot: Ashgate; 2007.

[2] Law of Oleron. Maritime Law History at (Accessed 23 April 2012)

[3] Woodall J. The Surgeon’s Mate (1617). Facsimile. Ed. John Kirkup Bath: Kingsmead; 1978.

Gordon E. Sailors Physicians: Medical Guides for Merchant Ships and Whalers, 1774-1868, J History of Medicine and Allied Sciences, 1993; 49: 139-156.

[4] Friedenberg Z. Medicine Under Sail. Annapolis: US Naval Institute Press; 2002.

Hudson G, Ed. British Military and Naval Medicine 1600-1830. Amsterdam: Rodopi; 2007.

[5] Lloyd C, Coulter J . Medicine in the Navy Vol III 1714-1815, Vol IV 1815-1900. Edinburgh: Livingstone; 1963.

[6] Lind J. A treatise of the scurvy. In three parts. Containing an inquiry into the nature, causes and cure, of that disease. Together with a critical and chronological view of what has been published on the subject. Edinburgh: Sands, Murray and Cochran for A Kincaid and A Donaldson; 1753.

Harvie DI. Limeys: the conquest of scurvy. Stroud: Sutton; 2002. 

[7] Lloyd and Coulter, Medicine in the Navy Vol III - IV.

[8] Bruijn I. Ship’s surgeons of the Dutch East India Company. Leiden: University Press; 2009.

[9] Bouchier I, ‘Some Experiences of ships’ surgeons during the early days of the sperm whale fishery’. Brit. Med. J. 1982; 285: 1811-1813.

[10] Steckel R, Jensen R. New evidence on the causes of slave and crew mortality in the Atlantic slave trade. Journal of Economic History 1986; 42:V2000)7: for the City of London’ress of Red Cross Societies 1926.10. Please take account of this in calculating any tax liabilit 57-77.

Haynes R, Shlomowitz R, Brennan L. ‘Maritime Mortality Revisited’. Int. J. Maritime History, 1996; 8: 133-172.

[11] Jones N. The Plimsoll Sensation. London: Little Brown; 2006.

[12] The National Archives (UK) File MT 9/31, Drafting Notes for Revising the Merchant Shipping Act (1867).

[13] Cook G. A History of the Seamen’s Hospital Society Oxford: Radcliffe; 2007.

Cook G. Harry Leach MRCP (1836-1879): the control of scurvy in the British Merchantile Marine, and the first Port Medical Officer for the City of London. J. Medical Biography, 2000; 7: 133-139.

Anon. (Attrib. Harry Leach). ‘Hygienic Conditions of the Merchant Marine’, Brit. Med .J. 1867 i, 36-37, 64-66, 89-91,120-122.

[14] Report of the Committee of the Society for Improving the Condition of Merchant Seamen. (London, 1867).

Williams D. Mid Victorian Attitudes to Seamen and Maritime Reform: the Society for Improving the Condition of Merchant Seamen, 1867. Research in Maritime History No 18: Merchants and Mariners: the Selected Maritime Writings of David M. Williams, (St Johns,Newfoundland, 2000) 229-252.

[15] Carter T, The Need for International Seafarer Medical Fitness Standards, International Maritime Health, 2009; 60: 1-5.

[16] Hugill S. Sailortown. London: Routledge & K. Paul; ‪1967 

[17] Kennerley A. British Seamen’s Missions and Sailors Homes 1815-1970. (PhD Thesis, University of Exeter, 1989).

[18] Carter T. Infections at sea past and present. International Maritime Health 2011; 62:157-159.

[19] Report of the Oslo conference on the health of the merchant seaman. Paris, International League of Red Cross Societies, 1926.

[20]Schilling RSF, Hazards of deep-sea fishing. Brit J Industr Med 1971; 28: 27-35.

[21] Roberts SE. Occupational mortality in British commercial fishing 1976-1995. Occ. Env. Med. 2004; 61: 16-23


*  Stanislaw Tomaszunas passed away in October 2011