I do not have any "real time" experience in 9-10 knots of wind with the Futura 111 because I do not have a Futura 111.
I do have an iSonic 111 and the boards are similar (certainly not the same) so I can pass along some experiences/ideas developed on the iS 111.
Couple of weeks ago, I got a new 7.8 m2 Sailworks NXslm 4 cam race sail.
I rigged the new sail and tuned it pretty well. but could not get the iS 111 to plane with this setup in 9-10 knots.
I put the same rig on the Futura 155 and was instantly planing.
The wind came up to 12-13 knots and I tried the iS 111 again and had no problem getting planing and a few planing jibes.
I currently weigh around 78.5 Kg (175 lbs.).
At your weight of 65 Kg. (143 lbs.) you may gain around 1-2 knots earlier planing for the same sail size.
So, the 8.5 could get you planing in 10 knots, but at 9 knots I'm thinking you would really need a wider board.
There's a huge difference between 9-10 knots and 12-13 knots, and I'm not certain that your lighter weight is going to make enough difference.
If you had a wider board (Futura 133/144) I am pretty sure you could get going with either the 8.5 Helium or the 8.2 Hellcat, but with the Futura 111 I remain pretty skeptical.
Hope this helps,
Last edited by Roger; 7th September 2009 at 10:40 PM.