General purpose seam compound is to be used above the waterline under topside enamels or below the waterline under antifouling paints. They are knifed into a clean, sealed, or primed seam. Seam cement is made from rosin and oils that are fully compatible with soft antifouling paints. Paintable after overnight dry. The cement is not too stiff and can be easily knifed into seams below the waterline.