I (85kg) currently use a F-type 158 w retro 10.0 and 70 cm fin as my low wind setup. My wife (59kg) has an F-type 138. I have three questions concerning low wind planing that i think you can answer
1. What size sail should get her planing at the low wind side of the spectrum (10 knot average winds) as soon as i am planing (assuming our skills are both at the intermediate/advanced level)?
2. what do you feel is the low end trade off for my FT158 and the new isonic 155 for my weight?
3. The difference in planing from my FT158 and my wife's FT138 if i use the same 10 meter sail is huge (at least 3-4 knots) for me when i use her board. is the isonic (assuming it is like the 148) closer to the FT138 or FT158?
Thanks for all the help over the years.