"first Tuttle box board in 1989 or 1990"

Yes I think I built my first Tuttle box slalom board in 89 and I had a new 13" (325mm) fin for my raceboard. The shaper kept on using it in his light wind slalom and that was a big fin at the time. As basher said bigger fins, better sails and everyone going faster with more us finbox failures.

The Tuttle box was an open design for everyone to freely use. Obviously on a lot of custom slalom boards. Even on wave boards for a few years.

Once you have a machined two piece mould the Tuttle boxes are easy to make and used off cuts of carbon.

Early 90s I remember seeing a production mistrial board with a power box and thinking why!