5.2.2.1 A companion hatch opening from a cockpit
or recess which gives access to spaces below the weather deck should
be fitted with a coaming or washboard, the top of which is at least
300mm above the sole of the cockpit or recess.
5.2.2.2 When washboards are used to close a vertical
opening they should be so arranged and fitted that they will not become
dislodged.
5.2.2.3 The maximum breadth of the opening of
a companion hatch should not exceed 1m.