Coded RIB at speed offshore

Coded vessel categories explained: Cat 0 to Cat 6

UK coded vessels are classified into seven Categories — Cat 0 through Cat 6 — based on how far from a safe haven they can operate. Lower numbers = further offshore = more rigorous equipment, stability and crew requirements. Here's what each Category actually means.

The big picture

Categories are an operating envelope. They don't describe what kind of boat you have — they describe how far from shore that boat is allowed to operate commercially. A Cat 2 coding cert means your vessel can operate up to a certain distance from a safe haven in a given sea state. Step outside that envelope and you're operating outside your certification.

The Categories run from Cat 0 (unrestricted ocean voyages) down to Cat 6 (rivers and inland waters only). Most UK charter operations sit between Cat 2 and Cat 5.

Each Category, plain English

CAT 0

Unrestricted

Operating area: Worldwide, no restriction.

Sea state: All conditions.

Typical vessels: Larger commercial yachts, sail training vessels, expedition charter.

Crew: Yachtmaster Ocean or equivalent professional ticket, full STCW.

Equipment threshold: Full SOLAS-aligned set, liferafts for full complement, EPIRB + SART, fire suppression.

CAT 1

Up to 150 nautical miles from a safe haven

Operating area: Open ocean within 150 nm of safe haven.

Sea state: Most conditions, with weather caveats.

Typical vessels: Offshore charter yachts, sail training, ocean delivery.

Crew: Yachtmaster Offshore Commercial minimum, ENG1, STCW Basic.

Equipment threshold: EPIRB + SART, two-VHF DSC, liferaft for full complement, full SOLAS pyrotechnics.

CAT 2

Up to 60 nautical miles from a safe haven

Operating area: Coastal and offshore within 60 nm of safe haven.

Sea state: Moderate. Most weather windows for charter operations sit here.

Typical vessels: Charter yachts, larger RIBs, commercial sailing schools, dive charters.

Crew: Yachtmaster Offshore Commercial, ENG1, STCW Basic, VHF SRC.

Equipment threshold: EPIRB now required (new under SPV Code 2025), SART, two VHF, liferaft, full pyrotechnics pack.

This is the most common Category for UK charter operations on the Antrim coast, the Solent and the Irish Sea.

CAT 3

Up to 20 nautical miles from a safe haven

Operating area: Coastal, within 20 nm of safe haven.

Sea state: Moderate, with weather restrictions.

Typical vessels: Day-charter RIBs, angling charters, smaller charter yachts.

Crew: Yachtmaster Coastal Commercial, ENG1, first aid, VHF SRC.

Equipment threshold: EPIRB now required (new under SPV Code 2025), liferaft, VHF DSC, full pyrotechnics.

CAT 4

Up to 20 nautical miles in favourable conditions, daylight only

Operating area: 20 nm in favourable conditions, day operations only.

Sea state: Favourable to moderate — defined sea state limit.

Typical vessels: Day-tripper boats, dolphin/whale-watching, smaller RIBs operating in summer.

Crew: Yachtmaster Coastal Commercial or equivalent, ENG1, first aid.

Equipment threshold: Liferaft, VHF, simplified pyrotechnics pack, daylight-restricted operating window.

CAT 5

Up to 20 nautical miles, daylight, favourable conditions, smooth/partially-smooth waters

Operating area: Sheltered coastal waters — estuaries, sea lochs, inside headlands.

Sea state: Smooth water (significant wave height limited).

Typical vessels: Sightseeing boats, fjord tours, ferry-like operations in sheltered areas.

Crew: RYA Day Skipper Commercial Endorsement minimum, ENG1, first aid.

Equipment threshold: Lifejackets per person, distress signalling, basic radio, simplified equipment set.

CAT 6

Rivers, lakes, inland waterways

Operating area: Inland waterways only.

Sea state: Inland — no sea state.

Typical vessels: River cruise, canal boats, inland waterway charter.

Crew: Boatmaster Tier 2 or equivalent inland ticket.

Equipment threshold: Inland-water equipment set, no offshore equipment required.

How to pick the right Category for your operation

The temptation is to apply for the highest Category your vessel could possibly meet — gives maximum operating flexibility. The cost: more equipment, more rigorous crew tickets, higher insurance, more frequent inspection. Pragmatic charter operators size their Category to their actual operating area, with a small buffer.

Categories vs jurisdictions vs Codes

These three terms get muddled. Here's the difference:

A vessel can be UK MCA Cat 2 under SPV Code 2025 and Irish PBL Class P4 simultaneously. Two certificates, two annual surveys, one vessel. More on Irish PBL Classes here.

What changed under the SPV Code 2025

The Category system itself didn't change — Cat 0 to Cat 6 stays. What changed under the new Sport & Pleasure Vessel Code 2025:

One record, every Category, every Code

CodedOK loads the correct schedule per vessel — pick the Category and jurisdiction, the right requirements load automatically. Free to start.

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Independent recordkeeping aid. Always consult your YDSA or MCA-recognised surveyor on Category-specific questions for your vessel.