How little sea time that is
Put the yacht route next to three other UK deck routes and the difference is plain. On this route all 12 months count as time signed on, whatever the yacht is doing, and only 6 of them have to be seagoing. Every other route below asks for watchkeeping or far more time on board.
| Ticket and starting point | Service the MCA asks for | Source |
|---|---|---|
| Chief Mate (Yachts) Unlimited, from OOW Unlimited | 12 months onboard yacht service as OOW, including at least 6 months seagoing, on a yacht of at least 500 GT. Time signed on counts. | MSN 1858 Amendment 2, sections 4.3 and 5.2 |
| Merchant Chief Mate Unlimited, from OOW Unlimited | 12 months watchkeeping service as OOW, in full charge of a watch at sea | MSN 1856 Amendment 1, section 3.3 |
| Master (Yachts) less than 3,000 GT, from OOW (Yachts) | 24 months onboard yacht service as a Deck Officer, including at least 240 days watchkeeping | MSN 1858 Amendment 2, section 3.6(a) |
| OOW Unlimited, from OOW (Yachts) less than 3,000 GT | 36 months in yachts | MSN 1856 Amendment 1, section 13.3 |
The short sea time does not make it an easy ticket. NAEST (M), the academic modules (unless you are exempt), the MCA assessments, ENG1 and the oral all still apply, and the certificate is yacht only. Both are covered below.
What the MCA actually says
Chief Mate (Yachts) Unlimited is one of the two Yacht Unlimited certificates the MCA introduced in MSN 1858 (M+F) Amendment 2, published 18 May 2026. Section 4.3 sets out the requirements. This is the entry route wording, word for word:
"(a) Hold either: A Master Yachts, less than 3000 GT, II/1, CoC; or An OOW unlimited CoC with a minimum of 12 months onboard yacht service as an OOW, which includes at least 6 months of seagoing service. All this service must be performed onboard a yacht of at least 500 GT. OOW Unlimited candidates must hold NAEST (M) Certification."
MSN 1858 (M+F) Amendment 2, section 4.3 · Read the full notice on gov.uk
12 months, and 6 of them count twice
The phrase that trips people up is "which includes at least 6 months of seagoing service". The 6 seagoing months are part of the 12. They are not an extra 6 months added on the end. The total is 12 months of onboard yacht service as an OOW, and at least half of it has to be seagoing.
The second thing worth knowing is what counts as service. Section 5.2 of the same notice defines onboard yacht service as time signed on, irrespective of vessel activity. The 12 months are not defined as watchkeeping service. That is a real difference from the merchant route, covered in the comparison below.
One timing point: plan on the 12 months being served after your OOW Unlimited is issued. The notice does not spell this out, so confirm with the MCA if you have earlier yacht time.
You also need NAEST (M). It is required for Chief Mate (Yachts) Unlimited whichever route you take, not just this one (MSN 1858 Amendment 2, section 6).
Who this is fast for: OOW Unlimited holders already working on yachts of 500 GT or more, and especially former cadets. A cadetship HND, Foundation Degree, Scottish Professional Diploma, DipHE, Advanced Diploma or Honours Degree from an MCA approved nautical college counts as a management level qualification, so those holders skip the nine academic modules.
Who it is slower for: if you gained OOW Unlimited through the HNC, CertHE or Advanced Certificate experienced seafarer route, that award is operational level. You do not get the module exemption and will need all nine modules.
The full checklist
Everything section 4.3 asks of an OOW Unlimited candidate:
- OOW Unlimited CoC.
- 12 months onboard yacht service as an OOW, including at least 6 months seagoing, all on a yacht of at least 500 GT.
- NAEST (M) certification, required on every route to Chief Mate (Yachts) Unlimited.
- The ancillary certificates in section 6 of the notice, including HELM (M), ECDIS, GMDSS GOC, Medical Care, Advanced Fire Fighting, Medical First Aid, PSSR, PSCRB, PST, FPFF and Elementary First Aid. Check section 6 for the exact list that applies to you.
- Nine academic modules at an MCA approved nautical college, unless you hold an MCA approved management level qualification (Honours Degree, Foundation Degree, Scottish Professional Diploma, DipHE, HND or Advanced Diploma) from an MCA approved nautical college. An HNC, CertHE or Advanced Certificate does not qualify for the exemption.
- MCA Assessments in Chief Mate Navigation and Stability (Yacht Unlimited).
- A valid ENG1.
- The MCA oral examination.
If you already hold Master (Yachts) less than 3,000 GT, you reach Chief Mate (Yachts) Unlimited through the other entry route in section 4.3, with no extra sea time.
Yacht route vs merchant Chief Mate Unlimited
The merchant certificate sits in a different notice, MSN 1856 Amendment 1. Section 3.3 there asks for 12 months of watchkeeping service as OOW. The yacht route sets a lower bar for what counts as service. The trade off is where the certificate lets you work.
| Chief Mate (Yachts) Unlimited | Merchant Chief Mate Unlimited | |
|---|---|---|
| Notice | MSN 1858 Amendment 2, section 4.3 | MSN 1856 Amendment 1, section 3.3 |
| Service as OOW | 12 months onboard yacht service, including at least 6 months seagoing, on a yacht of at least 500 GT | 12 months watchkeeping service |
| What counts | Time signed on, irrespective of vessel activity (section 5.2) | In full charge of a watch, 4 hours in 24, on a voyage |
| Also on this route | NAEST (M), nine academic modules (unless exempt), MCA assessments, ENG1, oral exam | See MSN 1856 Amendment 1 |
| Where it applies | Yachts only | Not restricted to yachts |
The catch: it is a yacht only certificate. In the MCA's words, it "does not grant Unlimited Chief Mate or Master status on any other vessel type". Section 4.1 of the notice also describes the Yacht Unlimited certificates as an interim solution. If you might want to move to merchant ships later, the merchant route keeps that door open and the yacht route does not.
Where to do the nine modules
Honest answer: as of 2 November 2026, we have not found a college publicly advertising the nine Yacht Unlimited academic modules. We will add the course to the YachtSync training directory as soon as one does. In the meantime, the directory lists schools for the ancillary courses on the checklist, and the MCA keeps the list of approved nautical colleges.
How YachtSync helps
The 12 months only count if you can prove them. YachtSync lets you log your sea time and keep every certificate on this checklist in one place, with expiry reminders before anything lapses. The Chief Mate (Yachts) Unlimited career pathway page lists every requirement, and the training directory covers 300+ providers for the courses around it.
Track the 12 months as you go.
Log your sea time, file every certificate and see what is left between you and your next CoC.
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Frequently asked questions
How much sea time does an OOW Unlimited holder need for Chief Mate (Yachts) Unlimited?
12 months onboard yacht service as an OOW, which includes at least 6 months of seagoing service, all on a yacht of at least 500 GT. The 6 seagoing months sit inside the 12, so the total is 12 months. Source: MSN 1858 Amendment 2, section 4.3.
Does the yacht service have to be watchkeeping?
Not for the 12 months of yacht service itself. MSN 1858 Amendment 2 section 5.2 defines onboard yacht service as time signed on, irrespective of vessel activity. The merchant Chief Mate Unlimited route is different: MSN 1856 Amendment 1 section 3.3 asks for 12 months watchkeeping service as OOW, in full charge of a watch, on a voyage. NAEST (M) is still required for Chief Mate (Yachts) Unlimited on every route.
Does yacht time before my OOW Unlimited count towards the 12 months?
Plan on the 12 months being served after your OOW Unlimited is issued. The notice does not spell this out, so confirm with the MCA if you have earlier yacht time.
Do former cadets need the nine academic modules?
Usually not. Under MSN 1858 Amendment 2 and MIN 720 (M) Amendment 1, a cadetship HND, Foundation Degree, Scottish Professional Diploma, DipHE, Advanced Diploma or Honours Degree from an MCA approved nautical college counts as a management level qualification, so those holders do not need the modules. OOW Unlimited gained through the HNC, CertHE or Advanced Certificate experienced seafarer route is operational level and does not get the exemption.
Can I use Chief Mate (Yachts) Unlimited on a merchant ship?
No. It is a yacht only certificate. The MCA states that it does not grant Unlimited Chief Mate or Master status on any other vessel type.
Which college runs the nine Yacht Unlimited academic modules?
As of 2 November 2026 we have not found a college publicly advertising the nine modules. We will add the course to the YachtSync training directory as soon as one does.
Sources
- MSN 1858 (M+F) Amendment 2, UK requirements for deck officers on large yachts (24m and over), sections 4.1, 4.3, 5.2 and 6. gov.uk
- MSN 1856 (M+F) Amendment 1, UK requirements for master and deck officers, section 3.3. gov.uk
- MIN 720 (M) Amendment 1, Transforming seafarer training: the UK's modernised officer qualifications syllabus (which awards count as management level). gov.uk
Last checked against GOV.UK on 2 November 2026. MCA notices are amended from time to time, so confirm the current version before you apply.
Related guides: Yacht Unlimited: the real shortcuts → · OOW Unlimited routes: yacht vs commercial → · Yacht sea service explained → · Master Yachts Unlimited →