Simon, I must read trough my collection of old "Multihulls" magazines to back up this, but I think the boats racing in "Thomas Crown" was Formula 40's (or Prosail 40's).
The tri in Waterworld was actually two identical boats, one rigged with the strange rotating rig and the other one with the traditional rig. In both cases, the full crew was sailing the boat from below deck!
Both boats was ordered brand new from France, and assembled in Hawaii before they was made to look 200 years old. The design was very hot and fast when delivered.
I remember "Multihulls" ran articles about both movies. Still have the issues in the bookshelf, but finding both would take some time..
"Thomas Crown" was on the TV here fairly recently and I really don't think they were F40's; these boats were not big enough. Also these boats sere using long hangling rack's for extra wrighting moment and I never saw a F40's with these over here (Full pelt had Hobie comfort type racks at the back for a while) but brosnan was on the end of a long "ladder rack" when they tipped it in....
