Sail Course Section 3 Boat Design and Hull

® Sail Course Section 3, Boat Design and Hull Types

® Sail Course Boat Design and Hull Types: Identify various hull configurations such as: a. Full keel. b. Full keel with cut away fore foot. c. Fin keel with balanced rudder. d. Fin keel with skeg rudder. e. Centerboard hull. f. Daggerboard. g. Leeboard.

® Sail Course Figure 3– 1 Entry Angle

® Sail Course Figure 3– 3 Full Keel with Cut-away Forefoot

® Sail Course Figure 3– 4 Fin Keel with Skeg Rudder

® Sail Course Figure 3– 5 Fin Keel with Spade Rudder

® Sail Course Figure 3– 6 Bulb Keel

® Underbody Shapes Sail Course

® Sail Course Figure 3 -7 Winged Keel

® Sail Course Figure 3– 8 Winglets on Keel

® Sail Course Figure 3– 9 Canted Keel

® Sail Course Figure 3– 10 Water Ballast

® Sail Course Figure 3– 11 Small Centerboard

® Sail Course Figure 3– 12 Daggerboard Hull

® Sail Course Figure 3– 13 Centerboard Keel

® Sail Course Note centerboard and pendant

® Figure 3 -14 leeboards Sail Course

® Sail Course Figure 3 -15 Bilge Keels

® Sail Course Figure 3– 17 Catamaran

® Sail Course Figure 3– 18 Trimaran

® Sail Course A cruising trimaran

® Sail Course Figure 3– 20 Transom Hung Rudder and Tiller

Sail Course ® Vocabulary Ballast. Weight carried low in boat to improve trim or stability. Board Boat. cockpit. Small (car top) centerboard sailing dinghy with very low topsides and virtually Centerboard. Pivoted board that can be lowered through a slot in the keel to reduce leeway. Daggerboard. Sliding board that can be lowered through the keel to reduce leeway. no Displacement. The weight of water displaced by a floating vessel; hence, the weight of the vessel itself. Gudgeon and Pintle. A metal eye and matching pin used to mount a rudder on the sternpost or the transom of a boat. Leeway. Sideways movement of a boat through the water, caused by wind or current. angular difference between the true course steered and the true course over ground. Stringer. A fore-and-aft structural member of a hull. Tiller. rudder. A lever attached to the upper end of a rudder stock, used by the helmsman to Wetted surface. The portion of a vessel’s exterior which is in contact with the water. Also, the turn the

® Sail Course Section 3, Supplemental Illustrations

® Sail Course Design Parameters - Intended use - Size - Aesthetics - Cost - Hull shape -- Minimum water resistance -- Maximum leeway resistance

® Sail Course Functions of Keel • Reduce Leeway • Lower Center of Gravity – Increase Stability

® Sail Course Boat Design Summary • Fiberglass most common hull material • Keels evolved from Full to Bulb – or Wing – Prevents leeway • Waterline length determines max speed • Wetted surface determines water friction