How many people fit on a 14-foot RIB, really

Short answer. Certification tells you how many people the boat can legally carry without swamping. It does not tell you how many can sit down at the same time without someone perched on a tube. Those are two different questions with two different answers.

01 · What the certification number actually measures

A CE persons rating is a flotation and stability calculation: it asks how many people of an assumed average weight the hull can carry and still meet buoyancy and stability requirements if swamped. It says nothing about how many of those people have somewhere to sit, or whether the boat still handles well loaded to that number.

02 · What comfortable seating actually needs

Comfortable capacity is a function of deck width between the tubes and how many dedicated seating positions the layout actually provides, plus room to move without stepping over someone. A boat can be certified for seven and comfortably seat four at speed, and that is not a flaw, it is simply two different measurements answering two different questions.

03 · The two numbers, side by side

On the ADB 420: the CE persons rating is 7, and the inside width between the tubes is 1.08 m (3 ft 6.5 in), which is what actually lets four adults sit without anyone on a tube. If a listing gives you only the certification number, ask for the inside beam as well. The gap between the two tells you more about real comfort than either number alone.