It's on the web site, 15m^2
http://www.hobie-cat.net/site_gb/?produits,hobie_16
or if you look at the class rules,
here http://www.hobieclass.com/site/hobie/ihca/downloads/rulebook/IHCARBook070523.pdf,
it says max 17.65m^2

nothing on the weight I can see anywhere though