Navigation Theory Overview: Day Skipper to Ocean

MGN 718 requires everyone holding a UK CoC or CoP, and anyone whose PSSR certificate is dated before 1 January 2026, to complete OneOcean module 0900 by 31 March 2027. It reverses MIN 729 (December 2025), which had said existing PSSR holders needed nothing more. The module is free, online, takes about one hour and gives a digital Verification of Training. Do it now: missing it may hold up your next revalidation.

MSN 1865 Amendment 1 Annex A lists only PST and FPFF refreshers for the OOW (Yachts) <3000 GT CoC. MSN 1858 Amendment 2 section 6 lists PSC&RB for that CoC with five-yearly updating, and MSN 1861 Amendment 1 lists PSC&RB and AFF refreshers for every revalidation. Updating PSC&RB also means updating PST, and AFF means FPFF. Until the MCA settles it, keep PSC&RB in date.

MIN 643 sets which foreign short-course certificates the MCA accepts and which courses may be taught online. The December 2022 edition carries an expiry of 30 September 2026 and no replacement had been confirmed. Under it, PST, FPFF, PSC&RB and FRB refreshers cannot be done online or peripatetically. Check gov.uk for the successor before booking a course abroad.

MIN 642 sets the routes from Y1–Y4 yacht engineer CoCs to Small Vessel CoCs. Its gov.uk note says it was extended to 1 December 2025; on 26 September 2026 it was still listed, not withdrawn and not replaced. It also cites the Chief Engineer <3000 kW oral as STCW III/2 where MSN 1904 says III/3. An MCA-approved college says Y-tickets can still be revalidated every five years, so conversion is optional for yacht work. Confirm the route with the MCA before paying for modules.

The ML5 form MSF 4112 Rev 02/23 is accepted for new referrals only up to and including 31 December 2026; use Rev 01/26 after that. Certificates already issued on the old form stay valid until expiry. A commercial endorsement needs an ML5 or an ENG1.

As printed, the ancillary table in MSN 1858 Amendment 2 marks both GOC and ROC against the Chief Mate and Master (Yachts) columns. The ROC will not satisfy the OOW (Yachts) route. Hold a GOC for any yacht deck CoC until the MCA says otherwise.

The Sport or Pleasure Vessel Code applies from 12 December 2025 and replaces the Yellow, Blue and Red Codes, MGN 280 for sport or pleasure vessels and the Intended Pleasure Vessels code, with a transition for existing vessels. The Master (Code Vessels <200 GT) oral syllabus still names MGN 280 and LY3, so know both old and new references.

Since 12 May 2025 the MCA approves GMDSS courses and issues certificates itself, on form MSF 4354. Exams are run by the training centre with a separate trainer and assessor, and a failed candidate may be allowed one resit within 2 weeks. The fees in MIN 716 (£77 issue, £54 standalone revalidation) come from a notice that expired on 31 May 2026; check current fees.

MGN 665 Amendment 1 (24 March 2026) makes registration of EPIRBs and 406 MHz PLBs on UK ships and watercraft mandatory, and failing to register is an offence. Check the yacht's beacons and any crew PLBs are registered with the UK Beacon Registry and the details are current.

MSN 1858 Amendment 2 refers to MSN 1865, MSN 1862 and MSN 1864 Amendment 2, but gov.uk showed only Amendment 1 of each when checked. xplor courses follow Amendment 1. If a later amendment appears, its requirements override what is taught here.

The Merchant Shipping (Accident Reporting and Investigation) Regulations 2026 (SI 2026/430) came into force on 15 May 2026 and revoke the 2012 Regulations. Serious injury means incapacitation for more than 72 hours starting within seven days. Evidence, including VDR data, must be preserved, normally for 30 days after notification.

The Mediterranean became a SOx Emission Control Area on 1 May 2025, with a fuel sulphur limit of 0.10% m/m. Engineers bunkering or changing over fuel for Mediterranean passages must plan to that limit.