Hi,
Sorry for the long intro...

Ever since enjoying my first SUP experience at Cocoa Beach during my last holiday, I've been wanting to do it again.
Compared to regular surfing, which I tried unsuccessfully some 15 yrs earlier, the learning curve with SUP is much less steep.
Since I also wanted to re-enter windsurfing again, I'm looking for a board that can do both. And I want to design and make it myself (I built 2 windsurfboards using vacuum technique in the ealy 90's).
I know there are wind sup's from most manufacturers but it alway seems a compromise of having either a good planing board for windsurfing or a good board for supping.
From what I understand, this has to do with rocker.

So I went looking for more information about rocker lines,... and came to the conclusion that there isn't alot of information about it.
All I really know basically is that because of the bigger tail rocker a sup gets propulsion from waves and this tail rocker prevents the same board to plane well using a sail.
Some solutions like windsurfing rocker with steptail (Exocet, Kona, RRD) look nice, but seem to emphasize windsurfing more than SUP. AHD Sealion and RRD Wassup look nice too, but I didn't find any rocker info...

Then, I found out about Simmons style sup's and how they behave differently in regard to speed and planing, but still are good to SUP. Some even have a planing section at the back.
Also I read that they don't use as much tail rocker and have hard tail rails, all being things that work well for windsurfing.
So has anyone tried to sail a Simmons style SUP? It should be best of both worlds, no?

I'd like to design one, 8'6" (250-260cm), +/- 150l volume as light wind, waveboard, or no wind SUP board. Spot would be North Sea (Belgium); mostly short and choppy swell.
Still have following questions:

- Do I miss something? Why hasn't anybody come up with this, or has there? Or will it simply not work and still be a compromise?
- What rocker values does a Simmons style SUP board have? Simmons history says almost no tail rocker, but based on pics I see, most seem to have 2" or more... I only find vague relative comments like: less tail rocker, more scoop, etc. but never absolute values.
- How would the wide tail of a Simmons affect windsurfing? It seems to work well enough for surfing. AHD Sealion also has wide fishtail...

Any input is welcome.