Seafarer Medical Certificate (ENG1 / ILO/IMO) Explained: What It Covers and How to Get One

The seafarer medical certificate — commonly called ENG1 in the UK system, with equivalent standards under the ILO/IMO Guidelines followed by most flag states — certifies that you're medically fit for duty at sea according to internationally recognized standards under STCW and MLC 2006. It must be issued by a doctor specifically approved or recognized for maritime medical examinations, not simply any general practitioner, since the exam follows a specific, standardized protocol.

The standard exam covers vision (including color vision testing, genuinely important for navigation lights and signal recognition), hearing, cardiovascular health, respiratory function, and a general physical assessment, along with a review of your medical history for conditions that could affect fitness for duty in a demanding, isolated working environment far from immediate medical care.

Specific additional requirements sometimes apply depending on your rank or intended vessel type — certain roles may have more stringent vision or hearing thresholds given their specific safety-critical responsibilities.

Uncorrected vision below the required threshold, significant color vision deficiency, certain cardiovascular conditions, uncontrolled diabetes, and certain psychiatric conditions are among the more commonly flagged issues — though many conditions that would initially seem disqualifying can actually be accommodated with proper management, documentation, and sometimes a conditional or restricted certificate rather than an outright failure.

Being honest about your actual medical history during the exam is genuinely important, not just ethically but practically — a certificate obtained by concealing a relevant condition creates real risk both for your own safety at sea and for the certificate's validity if the concealment is later discovered.

Validity periods vary by age and sometimes by specific flag state requirements, but commonly run for one or two years for most adult seafarers, with renewal requiring a fresh full examination rather than a simple extension. Planning renewal timing so your certificate doesn't expire mid-contract — which can create genuine complications — is worth building into your own career planning, alongside the certificate tracking covered in our broader guide on [STCW certificates](/blog/stcw-certificates-explained).

Address any manageable health issues (blood pressure, for example) proactively before the exam rather than hoping they go unnoticed, since proper management ahead of time is far better for both your health and your certification outcome than concealment. Bring your full medical history and any relevant documentation (medication lists, prior diagnoses) to give the examining doctor a complete, accurate picture. If you have a condition that might affect the outcome, it's often worth discussing with the examining doctor directly and honestly before the formal exam, to understand your realistic options.