Christenson Keel Twin The Christenson Keel was designed with retro twin fins in mind. This keel template is the most upright keel in the Futures line. It allows for great speed and control down the line, making it one of the most versatile keels in the Futures line up. Construction | Fiberglass Side Fins Area 23.42 Height 4.91 Base 6.50 Foil FLAT Angle 3.0