Thanks for the replys. This is taken from the RCD website.
a conversion of a watercraft which changes the means of propulsion of the watercraft, involves a major engine modification, or alters the watercraft to such an extent that it may not meet the applicable essential safety and environmental requirements laid down in this Directive.
The first part is clear to me that im exempt however the second part is not. I bought the boat with BSC certificate however im doing the work on a hard stand in essex so do not need to keep it up to date untill relaunch. I am unsure where the boat will be kept once finished so at a minimum i am working to BSC regs.
My boat is not CE marked.