Interesting shot of what I believe to be circa 1983 Diamond Head. Australian superstar, Tom Luedecke KA-1 sailing for Tiga on a 1984 Neil Pryde Fully Battened being the latest sail at that time designed by Monty Spindler. To leeward is Eric Thieme another member of the Tiga team. How things have changed: Notice the high booms and much higher off the deck rigs since masts were mounted much farther forward and the sails were higher aspect and the draft was located differently as well. The sail being used by Tom was designed by Mike Waltze, Matt Schweitzer and Spindler who worked together developing the Neil Pryde wavesail design "Ultranova". That was claimed by some as the "first serious all-full-batten wave design". However both Simmer Style and Ezzy Sails (?) were producing fully battened sails around the same time as I recall.

Yep. I also remember that the battens in most of those early production sails were so soft that they were next to useless at helping stabilise the sails. And it quickly became a 'thing' soon after to spruik sails without full length battens for wave sailing to allow the sail to 'luff' easier when screaming down a large wave. Some North 'Ezzys' came with optional short battens as well as full length. And in the below example, the 'Tri-batten system' even allowed you to fit a soft camber inducer for 'Speed and Slalom' sailing!

From what I think is the 1986 North Windsurfing sails brochure:

The apple doesn't roll far from the tree. That pic of a young Dave Ezzy looks so much like Graham Ezzy does today.

Yup, had 4.1 to 6.1 in Tri Radials for early 1984.
Switched to Hood Sails, just like the one pictured, up to 6.2, by mid season.

uweh said..
Hood Sails are they designed from Jeff Henderson ?

In the early 1980s up until mid 1985 Jeff Henderson was I believe the sail designer, when he left to set up Hot Sails. I recall even Peter Cabrinha was noted in magazines as using Hood sails in the early 1980s before he went to Gaastra. I think Hood Windsurfing shutdown in the mid 1980s.

^ If I'm not mistaken he recommended less twist for high winds and more for light winds.
I've been doing it wrong.