Entry & progression
MO74 s4(1) is the outer wall of your authority. Less than 3000 GT. Commercial use for sport or pleasure. No cargo. No more than 12 passengers. Step outside any one of the four, and the vessel is not a yacht — and your certificate does not reach her.
Limb 1 — less than 3000 GT
A hard ceiling. Above it, MO74 has nothing to say and neither does your ticket. Note that gross tonnage is a volume-derived number, not a weight — Lesson 4.3 — which is why builders design so carefully to sit just under a threshold. If a refit adds enclosed volume, the GT can move. It is not a fixed property of the hull.
Limb 2 — commercial use for sport or pleasure
The vessel must be in commercial use. A private yacht, used privately, is a different animal in most regulatory systems — different certification, different crewing, different insurance. Yachts cross this line seasonally, and a vessel that is 'private' on Monday and 'commercially chartered' on Friday has changed her regulatory character, not just her paperwork.
Limb 3 — no cargo
A yacht carries no cargo. Where exactly the boundary sits between the yacht's own tenders, toys and stores on one side, and cargo on the other, is not defined in the source material this course is built from, and we are not going to guess at it.
Limb 4 — not more than 12 passengers
This is the limb with teeth, because it is the one that is casually breached. Twelve is the number in the definition. Cross it, and two things happen at once: the vessel ceases to be a yacht for MO74 purposes, and — under the international convention framework — a ship carrying more than 12 passengers is a passenger ship. That is an entirely different regulatory world: different construction and subdivision standards, different damage stability, different certificates, different crewing. You do not get there by adding a thirteenth wristband.
WARNING — The count is a legal count, not a headcount Who is a passenger, as distinct from crew, an owner's representative, or a technician, is defined by the vessel's flag and the convention regime that applies to her — not by MO74, and not by the charter agreement. Get the definition that applies to your vessel from your flag and your DPA, in writing, and count against that. A charter broker's understanding of who counts is not a legal opinion.
The commercial reality of the charter
- The charter agreement sets the itinerary, the delivery and redelivery points, and the advance provisioning allowance. It does not set the weather.
- The broker sells an experience. You deliver a voyage. Those overlap most of the time and diverge exactly when it matters.
- The guest expectation is that the itinerary happens. The master's job includes managing that expectation before departure, not litigating it at 0300 in a gale.
- Charter start and end dates create the schedule pressure that Lesson 2.4 warns about. Name it out loud with the crew, so everybody knows it is a hazard and not a duty.
The master's authority to say no
The commercial arrangement runs between the owner, the charterer and the broker. You are not a party to it. Your obligations run to the safety of the vessel and the people aboard. When those conflict, the safety obligation wins, and every well-drafted charter agreement in the industry says so in a clause most people never read. Read yours.