The existing anti-fouling has been on the hull for at least six years (the time since the previous owner last used the boat). The boat as far as I know has been dry stored and the remaining anti-foul has become hard and brittle. It has worn though, in places on the keels exposing the iron which has rusted, there is also some barnacle encrustations on the GRP hull bottom.
The anti-fouling will be completely removed from the hull and the twin iron keels. I am currently considering what method I will use.
The quickest and best course of the action for the cast iron keels will be to grit blast the keels to remove all of the impurities and rust in all of the craters and pockmarks. This may have to be done by a specialist to get a good enough finish that a protective primer will adhere to which will raise the project budget. An alternative may be grinding using fibre disks to get the bulk of the rust off then using a DIY blaster to clean out the craters.
The GRP will be stripped using a combination of scraping, anti-foul remover, and sanding. The quickest option would be soda-blasting but the expense of the soda, equipment, labour will raise the budget significantly. As the waterline length is only 14ft it won't take too long but it will be a bit messy and awkward.
I am considering which anti-fouling will be reapplied to the hull; a lot will depend on whether the boat will be kept on the water, trailer, allowed to dry out etc.