Antifouling primer

I have a boat with an Iroko hull that was antifould last year with international cruiser but has then spent the year on dry land. I notice that some of the antifoul has gone powdery and flaked of but there is no evidence of primer. I am wondering whether to strip right back and prime, put a tie coat on or just sand back before putting on the new antifouling, any suggestions?

Roly, Voya Con Dios, Glasson, Lancaster

By all means, prime, particularly if the boat will not stay in salt water.

Antifouling paints are generally porous.

Bernard Vivegnis, Brussels