OK, here's the "big" issue here.
The 2005/2006 F-Type 138's are 88 cm wide.
The 2004 Free Formula 138 was 96 cm wide.
These are all very early planing designs.
They will work really well in sub planing to about 14 knots.
You can sail them in alot more wind, but the chop vs the width does not make for a real good combination.
The Futura 122 (71.5 cm wide) and the Isonic 122 (75.0 cm wide) are not going to be much fun and give much planing performance in the < 12 knots range.
How much sailing do you do in the 8-12 knot range?
Below 8 knots is the domain of your 12'6" SUP, right?
So, if you choose the F-Type (I'd look for an F-Type 148 or 2004 Free Formula 138 (wish I'd kept the one I had) due to the extra width) you get early planing performance down below 10 knots.
If you get the Isonic or Futura 122 you have a pretty big hole between 8 knots and about 12 knots.
For early planing performance in light winds (8-12 knots) requires either width; great skills; or both.
I sailed the 2008 Futura 155 (85.0 cm wide) this afternoon with the 2008 7.5 m2 Sailworks Retro and Lessacher Design 36 cm Duo Weed in about 10 knots and was planing most of the time.
Maybe the Futura 155 would be a better choice to fill the gap between 8-10 knots and a solid 15 knots when you can use your Trance.
As to specifics, for the F-Type 138 (88 cm) you could get going very early with a 9.5 m2 rig. The board works pretty well all the way down to about 6.5 m2 but that's a little beyond it's best range. 7.5-9.5 m2 is a more realistic range for this board.
The Isonic 122 works great with an 8.5m2. I was often the only one out planing last year in Bonaire on the Isonic 122 and an 8.5 Sailworks NX4 slm. I could get going in about 11-12 knots.
The 2008 IS 122 may be better but I do not have one to sail this year.
The Futura 122 probably works the best with 6.5-8.5 m2 rigs but again, like the Isonic 122, it's not going to be much fun (unless you have superb pumping skills and super light in weight) in < 12 knots.
Hope this helps,
Last edited by Roger; 23rd July 2008 at 08:37 PM.