For boats 0′-18′ with beams to 7′-3″ and low windshields. Use three vents for proper ventilation. One roll covers 7-8 boats. 14’x150′ – For runabouts 14′-19′ with beams to 8′-0″ and full width wind-shields. Use three vents for proper ventilation. One roll covers approximately 6 boats. 17’x270′ – For pontoon boats with 8′-0″ beams. Cuddy Cabins 17′-24′ with full windshields and bow rails. Use four vents for proper ventilation. One roll covers approximately 8 boats. 20’x100′ – For Express Cruisers 22′-26′ with beams 8′-0″ – 8′-6″. Use four vents for proper ventilation. One roll covers approximately three boats. 24′ x 115′ – For Express Cruisers with arches or small flybridges 25′-29′ with beams up to 9′. Use six vents for proper ventilation. One roll covers approximately 3 boats. 32’x 65′- For boats 32′-36′ with wide beams and flying bridges. Use six vents for proper ventilation. One roll covers 1 boat. 17x 120- For pontoon boats and Cuddy Cabin Cruisers 17- 24with.