Will be keeping our Mac on a river for most of the year taking her out for the odd mac rally and trip to the sea, I can't tell if she ever had antifoul before , the hull is just dark brown with a little bit off a texture after I cleaned her up.

Question is, do I need to put an undercoat on before I antifoul her (Already got got hard black) or can I just go a head (Only reason were antifouling is that there are river mussels where we are , River nene) .

Si