Join Date: Sep 2005
Location: New Westminster, BC
Thanked 587 Times in 558 Posts
Rep Power: 17
A 170 genoa is intended for light winds only, and will be severely stretched out if its wind range is exceeded, hurting performance as you believe.
A 153% genoa will incur no rating penalty... maxing out at 135 will give you a rating credit.. either move will likely result in improved results on the score sheet - and likely on the water as well.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)