Updated January 2026 • UK MCA / GOV.UK aligned
What’s the Difference Between an ENG1 and an ML5?
Most candidates are searching for one answer: which medical do I actually need for my job and vessel?
This guide makes it simple — with a quick decision checklist, a side-by-side comparison, and the most current UK rules.
For the official GOV.UK overview, see:
Seafarer medical certificates (ENG1 & ML5).
TL;DR (Fast Answer)
- ENG1 = seagoing “seafarer medical” (merchant ships & yachts, and some fishing situations). Issued by an MCA Approved Doctor.
- ML5 = domestic/inshore/inland + some small commercial roles (e.g., Area Category 2–6 up to 60 miles). Can be completed by any GMC-registered doctor (not necessarily an MCA Approved Doctor).
- If you might work further afield, on larger vessels, or internationally, ENG1 is usually the safer choice.
Official GOV.UK guidance:
Seafarers’ medical certification guidance.
Which One Do You Need? (60-Second Decision)
You typically need an ENG1 if you are:
• a seafarer / master / officer / crew on a merchant ship or yacht
• working on a fishing vessel where any ENG1 trigger applies (see fishing section below)
How to apply for ENG1:
GOV.UK – How to apply
You typically need an ML5 if you are:
• on UK inland or inshore waterways / domestic passenger operations
• master/crew on a small commercial vessel certificated Area Category 2–6 (within 60 miles of a safe haven)
• on a fishing vessel where none of the ENG1 triggers apply (see below)
Download the ML5 form (MSF 4112):
GOV.UK – ML5 medical report form
If you’re unsure, match the certificate to the most demanding scenario you may be asked to work (area of operation, voyage duration, foreign port inspection, and employer/flag requirements).
Fishing Vessels: The ENG1 vs ML5 Triggers (UK Rules)
GOV.UK lists situations where ENG1 is required for fishing vessels. You need an ENG1 if any of these apply:
- the vessel needs to be inspected at a foreign port
- the vessel is over 24m long
- you’re at sea for more than 72 hours
- you’re fishing more than 200 miles off the UK coastline
- you’re fishing beyond the continental shelf
Official sources:
GOV.UK seafarer medical certificates
and
Fishing medical fitness Q&A.
How to Apply (Simple)
ENG1 application
Book an examination with an MCA Approved Doctor. Official application steps:
GOV.UK – How to apply for ENG1.
ML5 application
Download and print MSF 4112 (ML5 report + certificate) and take it to any GMC-registered doctor with a licence to practise:
GOV.UK – ML5 form.
Common Mistakes (That Cause Delays)
- Choosing ML5, then later discovering your job/voyage requires ENG1 (re-booking + lost time).
- Not matching the certificate to the vessel’s operating area and voyage pattern.
- Leaving medical renewal too late before joining a vessel or planning your training/exam timeline.
Preparing for MCA Exams?
Your medical is only one piece of the puzzle. Our structured prep (e-learning + twice-weekly live clinics) is designed to help you explain answers clearly and confidently — the way examiners expect.