Do a search for CORGI website. You can get info on local fitters from the website using your postcode and selecting the type of work (ie boats)from a drop down list.
Or try phoning a local boatbuilder.And ask who they use.Im not sure if David Abel Boatbuilders is still in business if they are they will be sure to know.
We enjoyed a few days at the Bristol Harbour Regatta again this year.Sailing across from South Wales.
I tried to find a Corgi gas fitter in the Medway area to carry out a marine safety check. I got a list of about 6 fitters in the area who had the marine qualification; ALL of them said that they no longer did marine stuff because the regulations were too onerous. After several weeks of trying, it became an easier proposition to persuade the insurance company to drop the requirement. So now thanks to the far too fussy safety regulations I have no safety check on my gas installation.