Screamer, like you i weight 86 kg +/-. that said in saltwater thus i don't need 30-40 knots to get on 75 liters. i would be riding 4-5 meter sails.
i will be on the waves for sure. mostly on shore though...unfortunately.
what i really want to know is how fast is this quad in a straight line as i am a minimalist and like boards to cover a wide range of possible conditions without giving the feeling that one wished one was on another board (size apart of course).