3.3. Buoyancy and flotation - The craft shall be constructed to ensure that it has buoyancy characteristics
appropriate to its design category, and the manufacturer's maximum recommended load according to section 3.6. All habitable multihull craft shall be so designed as to have sufficient buoyancy to remain afloat in the inverted position. Boats of less than six metres in length that are susceptible to swamping when used in their design category shall be provided with appropriate means of flotation in the swamped condition.
3.4. Openings in hull, deck and superstructure - Openings in hull, deck(s) and superstructure shall not impair the structural integrity of the craft or its weathertight integrity when closed. Windows, portlights, doors and hatchcovers shall withstand the water pressure likely to be encountered in their specific position, as well as point loads applied by the weight of persons moving on deck. Through hull fittings designed to allow water passage into the hull or out of the hull, below the waterline corresponding to the manufacturer's maximum recommended load according to section 3.6, shall be fitted with shutoff means which shall be readily accessible.
3.5. Flooding - All craft shall be designed so as to minimize the risk of sinking. Particular attention should be paid where appropriate to:

cockpits and wells, which should be self-draining or have other means of keeping water out of the boat

interior,

ventilation fittings,

removal of water by pumps or other means.