Davis Whale Tail XL [448]Whale Tail XL Aluminum Stabilizer and Ski Boat Fin Improves performance in any I O or outboard motor! The Whale Tail XL extends out behind the prop to utilize prop wash energy which is normally lost. Whale Tail transforms this energy into lift for immediate response when the throttle is applied. Unique hydrodynamic design Stabilizes bow light boats Pops skiers up in less time Flattens wake for water skiing; creates positive, skid free turns: With bow