Min waterline height is 250mm to the lowest part of the transom to the WL.
I have in the past raised the point that where there is a cut out for the transom for the engine this area is minimal.
However a cut and dry surveyor could read quite absolute.
There are two solutions in this case.
1. Buy a longer length ouboards and increase the transom height (quite easy).
2. Build a second internal transom of say ply from tube to tube with integral drains.
With regards to TRUEs original point on build then the new codes request a build that would conform to SOLAS standards (on over 8m boats or ISO under). We SOLAS equivalence in place with full stability books etc etc.
TRUE refers the CE, ie RCD, and whilst this confirms a standard does not confirm a commercial standard.
The market has a quite mixed set of standards with ISO, RCD and MCD/SOLAS with taking into acount Lloyds, Veritas etc.
For the new codes ISO is accepted up to 8m, RCD is in theory only for recreational craft and a build to full SOLAS for most companies is expensive. However there is some latitude with the certifying authority who will look at all paperwork components.
John Fernley . MD, at MEACL is well recomened as being very thorough but pragamatic.
A mindfield for all but if the boat and operator have the right attidude then even with further correct stability and drop tests with decent scantlings then a good hull should achieve the grade.
Do not forget that the purpose of coding is to maintain a standard whereby the protection of passengers and crew is paramount
This will result in some hulls failing as they are not suitable for the purpose. ie. a RCD hull does NOT mean it is suitable for passengers.
If we can help by e-mail then feel free to fire questions.