fin length

Question
QUESTION: Hello!

I have  an almost brand new  Tabou Rocket 145 lts. For all its much vaunted reputation, I have come to realize that the lack of a retractable centerfin practically makes these types of " ultra-performing" boards  a piece of drifting deadwood, at least when one has to go upwind, unless the winds are strong enough for planing.

The place where I practice is a small, sheltered bay which  requires some aggressive upwind to get out in the open and have fun. The problem is that I find it hard to crank it upwind when the winds are light. If the board is not planing and I try to push the fin to create some lateral resistance, then the rear  sinks because there is not enough speed to sustain my weight on  the back. Even banking on the windward  rail does not help too much, unless the board is already planing and speeding.  
I was wondering if I could improve its upwind capability by replacing the  standard 48 cm fin with a longer one . How long?

Thank you

Franco

ANSWER: Hey Franco,

Putting on a longer fin may help a bit to get you upwind in light winds, but the drawback is that once you are into the planning winds, the longer fin may be too long and create more problems. Too long a fin in higher winds can cause too much lift and you get what is known as 'tail walking'. This is the tail of the board so high in the water that you loose control of the board. Too much lift can also cause the fin to spin out which most often leaves you in the water.

Trying to get upwind with any board that doesn't have a centerfin is a difficult task. Putting pressure on the fin the way you describe does nothing but put pressure on the tail. For light wind upwinding, foot position is key. You only put pressure on the fin when the wind picks up and is enough for planing. I've added a couple of 'how to's to help you understand foot/body/sail position for light wind upwind and light wind planing.

http://windsurfingmag.com/how-to/2008/04/03/balancing-act/

http://windsurfingmag.com/how-to/2008/04/03/light-wind-planing/

Hope this helps.
Keep on sailing,
Windlover

---------- FOLLOW-UP ----------

QUESTION: Thank you!
Yes, I was aware of the spin-out and " tail walking " risks with a longer fin, but I was hoping  that the winds I feel comfortable with for planing at my level are too  moderate to create these problems on ongoing basis, especially if I don't increase the length of the fin too drastically. My fin is 50 cm long. Would a 60 cm fin be really too  much? If so, perhaps anything in between would do.  Tabou offers  50 and  52 cm slalom lengths, but then the increment is really too marginal to make a difference, I think.

Perhaps a little more "schlogging" savvy is worthwhile considering.


By the way, the schlogging technique  at http://windsurfingmag.com/how-to/2008/04/03/balancing-act/ says that I have to keep the mast upright. I always thought that to go upwind the mast had to be tilted backward. Does it mean that to turn the board upwind (and to keep it on an upwind course) I don't have to worry any longer about tilting the mast backward? Just place the feet on the centerline, keep the mast upright,  don't sheet in too hard, rather sheet out and rake in gradually until I find the right" forward"  spot?

Thank you for your comments

Franco

Answer
Hey Franco,

Going to a 60cm fin would probably have minimal effects until you reach the upper wind ranges of the sail you are using.

Tilting the mast forward and back is more of beginner method of steering the board. Once a sailor has learned the techniques of board steering, they can better utilize the power of the sail for simply  power. In light winds, a fully upright sail will work better than one that is raked back. With the sail more upright, you will get more power and then keeping the board going where you want it to is controled by the feet.

Hope this helps.
Keep on sailing,
Windlover