An excellent article on getting the best out of yourself and your kit by John Smalley , 8th at Walvis (just behind Chris I think).
unionalarm.com/
Great article Dave.
Just wondering about the close to beach thing, is that just about chop, or is there something like the ground effect thing that happens with very low flying aircraft????
A pressure wave under the board that adds to lift perhaps????
I would have thought it was the chop. It doesn't take long for chop to build , even 25m off can be a lot lumpier than 10m and the rise was quite shallow at Walvis so they probably would have been out in the chop. Bjorn I think cut a slalom fin down to 16cm and Chris was hitting the bottom with his 20cm asy.
There may be something in the skimboard effect but does it matter if it is chop or ground effect? Closer is faster.
Having said that, Martin Van Meurs at West Kirby and Chris L at Sandy Point have hit 2 second peaks of 49kn+ and the water is flat but quite deep close to the edge so that would suggest water state is more important than depth.
quote:
Originally posted by yoyo
There may be something in the skimboard effect but does it matter if it is chop or ground effect? Closer is faster.
That was my belief as well. Pt walter is much the same though perhaps lumpier and windier further out. However at Walvis and SP the wind is pretty well undisturbed right at the waters edge. The sand at those places is very smooth.
quote:
Originally posted by decrepit
Great article Dave.
Just wondering about the close to beach thing, is that just about chop, or is there something like the ground effect thing that happens with very low flying aircraft????
A pressure wave under the board that adds to lift perhaps????
Walvis was an interesting place to sail. The wind seemed to be stronger closer to the shore- in the first round it was almost 10 knots stronger than 100m out. The other important thing with Walvis was the square angle. This made power and efficiency king. Chop impacts dont just increase the board drag, they also have a momentary increase in fin load. The fin loads are so much higher on a square course that chop impacts have a much greater effect on overall efficiency compared to a broad course. Also, there was probably an efficiency gain from increased board and fin lift from sailing in such shallow water. So the closer you got to the beach, the faster you went. Problem was the little waves dumping on the beach, and sucking the water out...
quote:
Originally posted by slowboat
Walvis was an interesting place to sail. The wind seemed to be stronger closer to the shore- in the first round it was almost 10 knots stronger than 100m out. The other important thing with Walvis was the square angle. This made power and efficiency king. Chop impacts dont just increase the board drag, they also have a momentary increase in fin load. The fin loads are so much higher on a square course that chop impacts have a much greater effect on overall efficiency compared to a broad course. Also, there was probably an efficiency gain from increased board and fin lift from sailing in such shallow water. So the closer you got to the beach, the faster you went. Problem was the little waves dumping on the beach, and sucking the water out...
