GENERAL: Designed For Rigorous Marine Use With Superior "B" Face Grades. All Struc 1, Group 1 Species Construction. Produced With "Ultra Core" Tight "High C" Grade Cross Bands & Centers. FACES: "B" And Better Face(s) Grade With No Open Holes Or Defects. Splits Over 1/16" Are Filled. Only Sound, Tight Pin Knots Allowed. Fully Sanded Faces Using 60 Grit Paper. BACKS: Single Faced Panels - "High C" Grade Chosen For Minimal Knotholes & Splits. Spilts Over l/16"AreFilled. Only Sound Tight Knots Up to l" Are Allowed. Back is Touch Sanded With 60 Grit Paper