Thanks for the reply Bob, but I'm sorry to have to say here on the "17 foot singlehanders" forum that that company is not dependable with respect to answering such questions.

Basically, I know enough when anybody can confirm the new alu mainsail to be of the same size as the old I-17R mainsail (carbon mast). Texel officials have officially measured the I-17R version and have found its mainsail to be 16.44 sq. mtr. by 8.53 mtr.

The EU F17 version can never have that amount of mainsail area and be F104 compliant. Also the specs have been "unofficially declared to be" : 15.34 sq. mtr by 8.69 mtr.

Source : http://class104.over-blog.org/pages/Mesures_des_principeaux_104-33825.html
(second source : http://www.nacraeurope.com/product.php?product_id=14&name=F17+One-up)


With a difference of this magnitude (12 sq. ft.) it will be easy for any US sailor of the new rig to spot the difference in mainsail area. Especially when both are layed on top of eachother.

Wouter