mark
my 4.5 dr valiant as spent most of its 18 months life on a mooring
and the hull looks crap it been anti fouled for next year by the last owner
it as two layers of anti foul and lots of staining
i am very carefully scraping the anti foul off useing a screw driver not the best way but its working then you will be left with lots of scratches were they keyed it to take the anti foul i then use mek solvent which ibs supplyed
for about £2.50 this will clean the paint and stains off then wash with water
i have filled the deep scratches with plastic padding grp repair and rubbed down
if your anti foul is the flaky type use a jet washer first this will remove the most of it and cut you work down which i have not done
dan