Update 2010:
For now i've got no faster results, there were no perfect conditions. However speeds on the bigger stuff do improve. Head-to-head (slalom) racing is a great way to improve my skills.

The material is up-to-date.
I'll go to the battlefield with the F2 Missile XS '08 and F2 SX 58 '09.. ofcourse with enough fins (23-25-26-27-30-31-33) and sails (5.1-5.5-6.6) to get high speeds.
Now wait for perfect conditions.. (soon I hope)

To bad there was not enough and stable winds at the Speedweek Gruissan 2010 for a result,
as you can see i'm sailing my 6.6 TR3:




Update 13 august 2008:
I've improved my fastest sailing session by a few km/h: gp3s session
71.42km/u is the max on this '2000 board!!

my fastest run untill now is the one I made on the 12th of march 2008.
It was a run at Herkingen with an angle of 90-100 degrees and doing some runs down into the chop. Before I made this session with the 5.4, I used my 4.2 Neilpryde search powerwave sail, because the 5.4 was to big for me at that time. With the 4.2 wavesail I managed to get a speed of around 63 km/h.
During the day, the wind decreased and it resulted in a flat water line behind the dam. When I was sailing the 4.2, the wind was 9-10 beaufort and it made the water come over the dam, so speedsailing was not really so easy.

For now I have some tips/tricks:
* A smaller fin is not always faster
using a small fin could result in a board sticking on the water and not flying over it instead.

I sometimes use a 32 cm fin under my sonic W52 in combination with the 5.4 sail! I also use the 30 cm fin under the same board but then in combination with the 6.6 sail. It all depends on the circumstances.

* A bigger sail is not always faster
Control is speed, when you are using big sails, it's not easy to handle and speeds will decrease.

* Play with the boom height
Boom higher is planing, Boom lower is control.

When you almost stop planing, you must hang as much as possible in your harness to keep weight on the front of your board instead of on the back of your board.

* Play with the mast position on the board
Mast forward is control, Mast backward is speed

* Keep an eye on you're stance
Front leg is stretched for control and lift, back leg is bend to catch the bounces of the water
When you're leaning forward, you will plane earlier. When you're leaning backward, you will have more speed, because the board will touch less water.

* Hold your mast in an almost 90 degree vertical angle with the wind; keep your sail up.
Keep your front arm stretched and the back arm makes the horizontal angle with the wind perfect.
It's not always easy, because the wind almost pulls you into an catapult, but it's the way to get as much wind as possible into the sail.

Ofcourse there are more little tricks, but I can't tell everything, I even don't know all tricks, otherwise I would be Antoine Albeau or Björn Dunkerbeck...

also check www.gps-speedsurfing.com for my gps speedsurfing results so far.