The actual directive is on the EU's site google
it. However the RCD isnt a simple as following a set of standards, its not like the ABYC system. The first thing is to follow all the ISO standards applicable to small boats, ( AC wiring
, DC wiring
, structural etc) these can be purchased from the ISO site.
If you want CE certification
either immediately or in the future then you really need to consider talking to a CE certification
experts (like CE proof in the UK). CE certification can only be done by specified bodies. Note if you are home building then you dont need CE certification as long as you dont sell it within 5 years. However if the boat is of significant value then you will find it impossible to sell without CE certification ( in the EU). CE certification is a lot more then just conforming to standards.