RE: Begintermediate on an X-186 Formula (2002 Vintage)
I like you handle! I have a *board formula 147, a *Board GO Friendship and a '93 Mistral Equipe XR, I also have owned and sailed a variety of NP V8 sails, including a '98 7.5 m which I still have. I weight ~80Kg.
Having read both James and Del's replies, I kinda agree and disagree with both!
The reasons that the Formula is not good for relearning are as James stated, plus it's construction is not meant to withstand numerous mast strikes,catapults, etc. that a learner will subject it to. The Non-skidd will be rough on your skin and if it came with the stock (70cm) fin, it will require you to use it in fairly deep water, which maybe frustrating depending where you sail and how good you are at waterstarting.
The formula will, in comparison to the Equipe, have a different static and dynamic stablity. The X-186 will be more stable in the across the board axis (100 cm gives you that) but it will be much more sensitive to your fore/aft body position. But being a 2002 formula board its less this way than say James's F158. (L=264cm vs 227cm)
You will have to honestly access your skills to figure if you would be successful relearning on the X-186. If you envision yourself stuggleing to maintain your balance and constantly having the rig catapult you or slamming the board, then you might be better off getting something more appropriate to a progressing windsurfer. If you picked-up the sport fairly quickly you might find yourself in the fast lane to "the planing joys of wideboard windsurfing." with the X-186.
One last peice of advice, You should tune your V8 with more leech twist (i.e. more downhaul) when sailing with the X-186. Your board speed and req't for low end sail power will be different than when sailing the Equipe Longboard.
I hope this helps you.