The ideal of every placement system is to place someone with all the required capabilities in each job. This ideal situation cannot always be met when taking decisions on medical aspects of fitness for maritime employment. First, the medical assessor will usually be assessing a person in relation to a predetermined set of statutory or employer specified standards. The assessor will not usually be aware of the details of the requirements for a particular  job on a specific ship, but be asked to decide whether a person is fit for a broad category of employment, for instance as a deck officer serving worldwide, or as a cook on a coastal ferry.  If they decide that someone is unfit then that will mean loss of employment. Statutory fitness systems have a degree of political cover from employers, trade unions and politicians who will, in approving regulations, have endorsed where the boundaries between fit and unfit should be set. Employer standards are likely to reflect the employers urge to avoid all operational and economic consequences from illness at sea and so be driven by labour market conditions and lack any social or political standing.

 The different points of view of different interest groups about fitness decisions make this a controversial topic. This controversy may either relate to how fitness standards are set or to how they are applied to individuals. Statutory standards can be challenged through political processes, those of employers can in principle be challenged in the courts, but this will usually require trade union or other financial support if a challenge is to be mounted and can be very complex where crewing is international. Most statutory systems have appeal arrangements that can be used to challenge individual decisions, but not the standards themselves. Individual decisions based on employer standards can only be challenged through the courts.

 The evidence base for seafarer medical standards is limited. There are a small number of relevant studies on seafarers, and while these provide limited information on illness arising at sea, they neither cover the accident and incident consequences of health related impairment, nor do they give information on the effects of interventions such as medical selection and lifestyle modification on illness or on safety at sea.[i] Relevant information may be obtained from studies in other settings, either in the transport sector or where work is performed remote from medical care.[ii] Frequently, studies of impairment and recurrence rates in the general onshore population are used to derive estimates of risk.[iii] Where such extended extrapolation forms the basis for standards there is a need for soundly based interpretation of its relevance to work at sea. It also increases the scope for challenges about either standards in general or individual decisions taken based on them.

 Given the inherent tensions the medical assessor has to be very clear about their ethical position.[iv] They need to make the purposes of the medical examination clear to the seafarer and observe good professional standards on confidentiality of clinical information as well as on disclosure of their conclusions.

 The prime purpose of a medical assessment in the eyes of the seafarer and the industry is the issue of a medical fitness certificate.[v] However, it also provides an opportunity to give the seafarer advice about health maintenance and about any health problems that might adversely affect their future career at sea. The place of such advice in the medical will depend on national custom and practice but it is normally seen by any health professional as one of their duties to anyone they examine. Where the seafarer may have a condition that could be related to their work, the need to advise them about the scope for securing compensation should also be seen as one of the medical examiner’s ethical responsibilities, irrespective of whether they are engaged or paid by the employer to carry out the assessment. If the examiner finds a medical condition that needs clinical investigation or treatment, they have a clinical duty to the seafarer to advise them of the need for treatment and to provide a letter of referral to an appropriate clinician.

 The timescale over which fitness is being assessed can have an important influence on the standards set, and this too has an important ethical element. Periodic statutory examinations normally aim to ensure that there is no significant excess risk over the period of validity of the certificate that is to be issued. Where risks of future disability are detected that are unlikely to pose a risk during the period of the certificate, the seafarer is normally advised of these but they do not preclude the issue of a certificate. For example a person who has diabetes treated by diet alone could be at significant risk of problems in the distant future either from the condition or from its treatment with insulin but would normally be considered fit. Different considerations may apply when a recruit to seafaring has their first medical and a condition is found that is likely to mean that their career will need to be terminated in a few years, for instance someone with borderline visual acuity. The decision here will depend on the legal and social framework, they could be advised against a career at sea, but issued with a certificate covering the time until their next medical or they could be considered unfit, particularly if they are likely to be unable to complete their training. Employers have, historically, sought to avoid employing those with long-term health risks, especially when there are abundant seafarers to recruit. They are increasingly avoiding long-term commitments to employment by engagement for single contracts and avoiding the risks and cost of future ill-health in this way.

 The seafarer can be seen as having a duty to disclose any health problems to the examining doctor, but given that they want to secure employment they may be reluctant to do so. A declaration signed by the seafarer stating that they have fully disclosed any relevant information is commonly used. Most statutory systems rely to a large extent on seafarer disclosure, with the sanction that failure to disclose could invalidate the certificate. Employer specified standards commonly rely on more extensive clinical testing than statutory systems, but the validity of the test methods used is variable and it is not uncommon for seafarers with false positive tests to be rejected without recourse to more detailed investigation. 

 Routine medical assessments are usually done on a periodic basis, for instance two yearly or on contract renewal. Illness may arise between medicals and it is good practice to ensure that seafarers are aware of the need to report any illness or injury that may be relevant to their fitness to work at sea, and then be re-assessed. Criteria may also be set for additional assessments, a period of illness or absence following injury of, for instance, more than three weeks; when certain classes of illness arise, or when specified medications are used.

 Continuity of assessment records can bring benefits as trends can be followed, for instance in visual performance or in weight.  This may be by means of return visits to the same examiner, by a medical record carried by the seafarer or by using a central database of medical records. Continuity can also provide the basis for constructing a personal risk profile for conditions such as vascular disease that can adversely affect future health. This can be the basis for more targeted information, advice or restrictions.