54 Slalom 1' = 34cm, 2' = 45.3cm with 1cm of rail tuck at the widest point. Bottom shape is single concave into double almost to the tail. 54 Speed 1' = 33cm, 2' = 42.2cm with 1.8cm of rail tuck at the widest point. Slight double concave with slight chine fading to v.