RE: How to avoid "spin outs"?
I had the opportunity to sail last weekend, not great conditions though. However, I used a 9m2 sail with JP Freeride 129 (width 69cm) and 48cm fin (Curtis CR12). Foot straps in the outer position and in second but last screw position. I don't know the wind speed. And I had spinouts 3 or 4 times.
Here are your questions and my answers:
When you put "pressure" on your fin, what is the rail to rail attitude (the roll angle) of your board? Are you sailing with the upwind rail lower than the downwind rail?
The upwind rails was actually higher than the lee (downwind) rail. I did it not by purpose but struggled to get the board horizontal at higher windspeeds.
Are you trying to sail "on the fin" with the lee rail slightly (very slightly) lower than the upwind rail?
Ref. rail position, see above response - lee lower than upwind by a fair bit it felt. I still try to understand how to ride "on the fin". I have the feeling that the wetted area is relatively large (and long) but don't know for sure - difficult to judge when on the board I find.
Are you trying to push the tail of the board down, toward the water, or trying to push the tail away from your body?
I wouldn't say that I try to push the tail in a direction but as a matter of fact I push it away from my body while I try to reduce the pressure by bending the back leg and straighten the fron leg. Occasionally I even try to "pull" rather than push with my back leg but I guess whenever I don't concentrate on my back leg I push away.
There were times that I remember when I tried to almost lift the front foot to lift the entire board a bit out of the water.
Water conditions rather flat (lake) but in gust some small waves/chops. Once the upwind rail got lifter from one of those small waves and I lost immediately grip (means spinned out).
The sail needed actually more downhaul I realised later. It was (just) ok for the lowest wind speed and got me to plane early but in the gusts I struggled to hold it. To same extent lack of practise (TOW) I presume.
Overall I felt reasonbly good, got to plane earlier than a guy with a 9.8m2 Nitro and was quite fast compared to others (although most had smaller sails)
Hope this helps you to get a better understanding what I do wrong and waht I could do to avoid the spinouts.