In that Windsurfing Magazine article there was also a mention of the "double surface sail with unique interlocking battens". Now this I had NEVER seen nor heard of before. I expected this innovation to eventually become a reality, but i had NOT anticipated that it would take over 15 years !!!
George was using this sail around 1990 - as per article... and enclosed photo:
Dan Kasler originally of Gaastra sails has already dabbled in the idea. This seems to have been around 2004. There were inflatable chambers that were aligned horizontally inside the sail. Never went into production.
In the race sailboats these are more solid structures:
I choose that video because they are using a SOFT sail and the narrative is a GOOD description...
Kites have been using tubes for some time and here is a video showing the power AND de-power
With all this activity in this innovation - why has this NOT gone into production ?? Here are some discussions... The obvious factors seem to be weight and cost. There is an element of transportability as well. How convenient or inconvenient is it to transport and rig ??
Now it seems a Russian innovator in N.E. USA is getting ready to go in production !!! What one can see in the photo below is 1) he has a dog :-) and 2) the tubes are going the other way - vertical to the water. In this forum discussion he discusses some issues that were overcome and how confident he is that this is going to be the sail / foil to beat !!!
As Geritt mentions in the comments, there is a lengthy discussion on the Dutch forum as well, If you clique the link, it will b translated:
There are other interesting photos as well:
"Although this sail was easy to rig, properly rotated, easy to trim it became nothing" <-- translation
Windsurfing has many aeronautic influences - example: James Drake. Foils seem to be a prevalent thought - from aviation. Sometimes tiny innovations on previous accepted concepts goes a LONG way. Now that the loose leech has been around for many years, it is becoming difficult to find a longboard sail with a traditional tight leech in North America !! Foot straps revolutionized wave sailing, bump n jump, free style, etc. How did people ever sail without a harness ? Perhaps the air bladder is only needed in a wide luff sail ?? This would save me from breaking my back when i try to uphaul a race sail :-) Maybe I should shove a noodle up the wide luff ?? :-)
In any case , these ideas like wing sails/power foils have been around and previously attempted.
Let's wish this fellow lots of luck and hope one day we will all benefit !!!!