After some thought and conversation with friends I decided to look and bodyboards as inspiration for the rails on "The Sled" hand plane. The chiseled 50/50 rail apex has never let me down. Below are images of the process I went through in shaping so far. Picking up from Pt. 1, I found the center of the rail and drew a center line and then found my front and rear rocker line.
From there I grew a center line on the bottom and basically made a grid to find reference points while shaping. The two most important intersecting lines are of the noes and tail.
The top rail gently slopes down at a lower angle much like a super bladey hull while the bottom comes up at a high angle like a bodyboard. I left the apex sharp. After some research I found that Tom Morey came upon the 45 degree rail by looking at old Hot Curl boards that did not use fins. Works for me!
I'm making this for the less than ideal small and mushy days. There is a lot of volume for a hand plane so who knows, it may be a dog in the water or it could fly! Keep in mind that I have never shaped a hand plane in my life. I'm just going on feeling.