Small hatches, which may be submerged in case of damage,
are those which are normally used for access by personnel. Such openings
are to be closed by approved quick-acting watertight covers of steel
or equivalent material. An alarm system (e.g. light signals) is to
be arranged showing personnel, both locally and at a central position,
whether the hatch covers in question are open or closed. In addition,
a notice board to the effect that the closing appliance is to be closed
while at sea, and is only to be used temporarily, is to be fitted
locally. Such openings are not to be regarded as emergency exits.