ISO certification for Wally-type "terrace on the sea"

Hello!

I am currently designing the aft deck of a personal project of mine, a 50ft sailing yacht, Class A (ocean going)

The aft deck is similar to some of the Wallys that have a "Terrace on the sea"

I am puzzeled about the certification of some of the wally yachts.

The Wally 80 Tango, which certainly has CE (ISO) certification ha the following sill on the campanionway:

http://m5board.com/articles/montecarlo/wsb.jpg

It seems to be about 30 cm high, which is compliant with the CE rule:

http://www.ibinews.com/ibinews/ebb/t9_fig3.html

Designs like the Wally Tiketitan and Esense seem to have much lower sill heights, more like 15 cm.

http://www.advmarea.com/ftp_farevela/17114559_esense.jpg

I can't imagine those large yachts to be only of Class C which permits a 15 cm sill height).

Does this mean that these large Wallys are not CE compliant? If so, Why can they get away with it? Does it have to do with the fact that they are custom built boats, and not mass produced yachts?

I basically want to find out what rules are determining this design, and if I can use them on my own project. (I obviously want a minimal sill height).

Anyone can ligth my darkness?:idea: