Look through any charter fleet and the same number keeps appearing. Yachts sleep six, eight, ten or twelve guests, and then the listings stop. It is not a coincidence and it is not a design limit. It is a line drawn in international maritime law, and it shapes almost every private yacht built for charter.
The short version: a vessel carrying more than twelve passengers is a passenger ship under international maritime law, and a passenger ship is an entirely different animal from a yacht. Staying at twelve or below keeps a yacht a yacht.
Here is where the rule comes from and what it actually means when you are booking.
Where the rule comes from
The number comes from SOLAS, the International Convention for the Safety of Life at Sea, which is the treaty that governs safety standards for ships worldwide. SOLAS defines a passenger ship as one that carries more than twelve passengers, and it applies a full set of requirements to any such vessel on an international voyage.
Those requirements were written with ferries and cruise ships in mind: watertight subdivision so the hull survives flooding, structural fire protection, evacuation and muster arrangements, life-saving appliances sized for a crowd, and the surveys and certification that go with all of it.
Below thirteen passengers, none of that applies in the same way. The yacht is regulated as a commercially operated pleasure vessel instead, under national rules and, for larger boats, flag-state codes written specifically for yachts.
So the twelve is not a safety judgement about how many people fit on the boat. It is the point at which a completely different rulebook takes over.
Passengers vs crew
This is the part that confuses people reading a listing, and it matters.
Passengers means guests. Crew are not passengers, so a crewed yacht carrying twelve guests plus a captain, a chef and a deckhand has fifteen people on board and is still within the rule. The captain and crew are counted separately because they are working the vessel rather than being carried on it.
There is a second distinction alongside it, between the number a yacht sleeps and the number it may carry. A yacht might have berths for ten but be certified for twelve during the day, or the other way round.
| Term | What it means |
|---|---|
| Passengers | Guests carried on board. Capped at twelve on a standard charter yacht. |
| Crew | Captain, chef, hostess, deckhand. Not counted as passengers. |
| Berths | How many people can sleep on board, which can be fewer than the carrying limit. |
| Cabins | What actually decides how comfortable a group of that size will be. |
The practical version of this is the gap between how many a yacht sleeps and how many it may carry, and it is the distinction that catches out groups booking near the limit. It is worth confirming for the specific catamaran or monohull you are looking at rather than for the model in general.
Why twelve
Twelve is not an arbitrary number, and it is not new. The threshold has been part of international convention for decades, and the usual explanation is that a small number of people can be managed, briefed and evacuated by a crew without the systems a ferry needs.
Above that number the assumption changes. A ship carrying a crowd needs organised muster stations, signage, trained evacuation procedures and a hull designed to survive damage while people are still on board. Meeting all of it costs a great deal and produces a vessel that no longer feels or handles like a yacht.
The consequence for the charter market is straightforward. Builders design to the limit, operators certify to the limit, and the fleet you browse is a fleet of yachts built for twelve or fewer. Charter catamarans are generally built for twelve guests or fewer for exactly this reason.
What changes above twelve
Carrying thirteen or more passengers is not impossible. It is a different category of vessel with a different certificate, and there are two routes to it.
The three tiers
- Up to 12 passengers. The standard commercial yacht. Certified under national rules and, for larger vessels, yacht codes written for this size of operation.
- 13 to 36 passengers. Possible under a passenger yacht code, a purpose-written standard that applies passenger ship principles in a way a large yacht can actually meet. Rare, expensive and, in practice, found on large yachts.
- Above that. A passenger ship under SOLAS in the full sense, built and certified as such. This is the world of ferries and cruise ships, not charter yachts.
For anyone chartering in Greece, the first tier is the one that matters. If your group is larger than twelve, the answer is usually two yachts sailing together rather than one bigger one, and that is a normal arrangement rather than a compromise. Greek law does allow professional pleasure vessels certified for up to 49 passengers, but those are a different class of boat from a standard charter yacht.
Day trips
The obvious objection: what about the boats that take forty people out for the day around the islands?
Those are certified differently. A day boat carries passengers for a few hours, does not sleep anyone on board, stays close to shore and is inspected and licensed as a small passenger vessel for that specific operation. Its certificate says what it may do, how many people it may carry and where it may go.
That is why the same island can offer a day cruise for fifty and a week-long charter for twelve. They are two different classes of vessel doing two different jobs, and the number on the certificate reflects the job rather than the size of the boat.
What you cannot do is put a large group on a day boat and keep it overnight, or add extra guests to a charter yacht because there is space on deck. The limits are on the paperwork, and the paperwork is checked.
What to check when booking
If your group is anywhere near the limit, three questions settle it before you get attached to a particular yacht.
First, how many guests the yacht is certified to carry, not how many berths it has. Second, whether children count, because they generally do, and a family of five is five passengers unless one of them is under a year old. Third, whether crew are included in the number you are being quoted, since on a crewed yacht they are not.
Then work backwards from cabins rather than from the headline number. Twelve guests on a yacht with six cabins is comfortable. Twelve on a yacht with four cabins and a convertible saloon is a very different week, and the certificate will not tell you that.
The fleet lists capacity for each yacht, and anything ambiguous is worth confirming in writing before you book rather than discovering at check-in.
When the number is close to the limit, get it confirmed in writing against the specific yacht rather than the model, because sister ships are not always certified identically.
Frequently Asked Questions
What is the 12 passenger rule?
Under SOLAS, a vessel carrying more than twelve passengers is classed as a passenger ship and must meet a much stricter set of construction, safety and certification requirements. Charter yachts stay at twelve or below to remain outside that category.
Does the crew count towards the twelve?
No. Crew are not passengers, so a crewed yacht can carry twelve guests plus its captain and crew.
Do children count as passengers?
Generally yes. The limit counts people carried, not adults, and only infants under one year are left out, so a family of five occupies five of the twelve places.
Can any yacht carry more than twelve guests?
Some can, under a passenger yacht code that allows thirteen to thirty-six passengers on vessels built and certified for it. These are rare, and for a normal charter the practical answer for a larger group is two yachts.
How do day trip boats carry forty people?
They are certified as small passenger vessels for day operations, with no overnight accommodation and defined limits on where they may go. It is a different certificate for a different kind of trip.
Sources
- Hellenic Coast Guard, Law 4256/2014: Tourist vessels and other provisions (in Greek). https://isktheea.hcg.gr/nomothesia/%CE%9D.4256-14.pdf
- International Maritime Organization, Safety and environmental standards on passenger ships. https://www.imo.org/en/MediaCentre/HotTopics/Pages/passengership-default.aspx
- International Maritime Organization, Passenger ships. https://www.imo.org/en/OurWork/Safety/Pages/PassengerShips.aspx
- legislation.gov.uk, Directive 2009/45/EC, Article 2, Definitions. https://www.legislation.gov.uk/eudr/2009/45/article/2
- Maritime and Coastguard Agency, MSN 1895 (M) The Red Ensign Group (REG) Yacht Code Part A. https://www.gov.uk/government/publications/msn-1895-m-the-red-ensign-group-reg-yacht-code-part-a/msn-1895-m-the-red-ensign-group-reg-yacht-code-part-a
- UK Ship Register, The Passenger Yacht Code. https://ukshipregister.co.uk/other-services/large-yacht-services/guidance/the-passenger-yacht-code/
Tell us how many are coming and we will show you what is certified for that number, and what it looks like split across two yachts if it is easier.
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