Stoneburner: The attached photo shows a board in a deep turn. When the board is moving the fastest and has a high roll angle (banked in turn and/or a very hollow wave) the stagnation line and spray root start at the inside rail just back from the nose and run to a point on the outside rail behind the forward fin. The fin in the upper left corner of the photo is obscured by the spray sheet peeling toward the outside rail. If the camera had a wider field of view, it would show the stagnation line/spray root intersecting the outside rail about eight inches up from the tail.
The video link at the start of the thread is from a hollow lined up day with deep bottom turns. The flows are relatively similar in small waves with less interval but the transverse flow angles are lower in those conditions.
In order to optimize the bottom configuration, we look at how much time the flow moves at certain angles. The bottom configuration has to cover a wide range of variables. The key is to focus on improving performance in the range of flow angles that occur most frequently.
One thing to keep in mind is the flow across the inside rail. The higher pressure in that region makes that flow very important. It may not be as obvious as the transverse flow over the shore side rail, but the tranverse flow over the wave side rail is critical.
