"The concept of the transitional rail is simple, a curved surface will creat less resistance than a flat surface, this maxmising speed & maneuverability. The rounded part of the rail creates very little resistance & just about eminates the spray that comes of flat rails.
The lower bottom rail is bevelled to add control. Combined with channels the speed & control are unmatched. I have been using transitional rails for over 25 years in all wave conditions"