I saw one being used at Gerroa only a few weeks ago.....I did have to ask what the hell it was as I'd never seen one in my time in the sport.
There was a famous Dutch windsurfer from the 80's - Stephan van den Berg - who inspired many people to experiment with the inverted harness hook shown in this example. Just attempting to date this object
After a 20+ year break from windsurfing I got back on the water with all modern gear. I wore the new (seat) harness over my shoulders for my first session 
Don't tell anyone...
Had one very similar in 1980 made by Dufour but was yellow and the hook was just a single wire, I had a few interresting moments trying to get free from the harness line caught under the sail!
I went back to the old trapeze harness!
i still have a maui sails HiPower, just like fred used when he smashed 26kts.
they were real popular with old guys who switched over from hobies.
Real men and women don't use harnesses!!
The man was Craig Masonville, the woman - I can't remember.
If you're under 40 - ask your dad.
