ISO 11812 interpretation

Hi to everybody,
i' have some interpretation questions about pleasure craft regulation ISO 11812.

the doubts are the following:
1) point 8.1 states "Watertight cockpits shall have no opening below the height hC"
-then point 9.1 states"All surfaces of watertight cockpits up to hC shall have a watertightness degree 1."
so is it allowed or not to have any kind of opening inside watertight cockpits, even if limited to grade 1 watertightness??

2) regarding quick draining cockpits, point 9.2.1 states "All surfaces of quick-draining cockpits up to hC shall have a watertightness degree 1 (...) The watertightness degrees of the closing appliances shall be as required by Table 6." and in fact those watertightness degree range from 2 to 4;
since the height hC can easily be more than hS, is the watertightness degree 2 actually applied?

for example, i'm concerned about main engine removal hatch watertightness degre. it'an enclosure placed on the bottom surface of the cockpit, so its watertightnesss degree should be 2, but is almost always below hc level (except for open cockpit boats), and accordingly should be degree1.
which one is the leading requirement? is it really possible to accomplish such high degree of watertightness with an engine removal hatch?

hope for an elucidative answer, i give to everybody my best regards

 

1 Yes it's allowed
2 No.. it's 1
and yes it's possible. Remember also the surface pressure on the hatch be the same as the deck around it.
BR Teddy