The five-year clock
Governing: STCW regulation I/11; MSN 1861 (M) Amendment 1, section 2; MSF 4201 Rev 11/25. Cross-refer: STCW refresher, ENG1 medical guide.
Why a CoC expires
A Certificate of Competency is a statement by a flag state that you are competent now. The STCW Convention, in regulation I/11, requires every Master, officer and radio operator who wants to keep serving at sea to have the certificate revalidated at intervals not exceeding five years, showing continued medical fitness and professional competence. The UK gives effect to this through MSN 1861 (M) Amendment 1 (December 2022), which replaced the original MSN 1861.
Yacht CoCs are no different. MSN 1858 Amendment 2 says a yacht deck CoC is issued and valid for 5 years from the date the qualifying conditions were met.
The 6-month window
This is the single most useful fact in this course. MSN 1861 Amendment 1, section 2.4:
| When the MCA receives your application | New expiry date |
|---|---|
| Within 6 months before current expiry | Fifth anniversary of the current expiry date |
| Earlier than that | 5 years from the date of revalidation |
Worked example
CoC expires 15 August 2027.
- The 6-month window opens on 15 February 2027.
- Application received 1 March 2027 (inside the window): new expiry 15 August 2032. No time lost.
- Application processed 20 January 2027 (outside the window): new expiry 20 January 2032. You have given up almost seven months (20 January to 15 August).
TIP — Diary the window Put two dates in your calendar: the window opening (expiry minus 6 months) and a deadline two months before expiry. Aim to submit in between.
What you submit
MSN 1861 Amendment 1, section 2.2, lists the standard package, submitted with MSF 4201:
- The completed, signed MSF 4201.
- Your original CoC (the current form accepts digital submission).
- Evidence of seagoing service (Lesson 1.2) or 30 months in an acceptable occupation (Lesson 1.3).
- Evidence of refresher training within the last 5 years in PST, FPFF, PSCRB and AFF (Lesson 2.1).
- Photographs to the form's specification.
- A valid ENG1 or accepted equivalent.
- Where applicable, ECDIS (deck) or High Voltage (engineer) training evidence to avoid limitations.
- The fee.
MSF 4201 Rev 11/25 gives fees of £64 (UK return delivery), £74 (EU/EEA) and £84 (rest of world), asks for submission by email to revalidation@mcga.gov.uk, and says the MCA aims to assess within 14 days of receipt.
CAUTION — Current rules apply MSN 1861 Amendment 1 section 2.6: you must meet the regulatory requirements in force when you submit, not those when you first qualified.
The yacht reality
Yacht officers usually have more sea service than they need, and less paperwork than they think. The revalidation problems that actually occur are:
- refresher certificates older than 5 years;
- ENG1 expired or about to expire;
- testimonials not verified, or signed by the wrong person;
- application sent a year early, losing months.
The rest of this course takes each in turn.