chadins said..
Well I am busted ha ha broke after the wing purchases: really getting pissed at all these apparently perfect foil boards with massive price tags.

Any tips for a prone board: got the sup sorted and have 2 original tuttle boxs to use (one left now for the prone board)
I was thinking old knee board?

For advice on this seek out George Greenough from Byron Bay. I believe he was creating windsurf boards using his kneeboarding and surfing experience and likely may be doing similar with foils today. Expect "anti-shark foils" as well that decapitate sharks on contact will be now being perfected following his experiments with metal fins in the 1980s. Please report back on how you go with George on this point.