Friday, November 14, 2014

Pumping the Board

Archie's NNE ~12-14Kn (20m)
Enough wind to get out for a quick solo session. First couple of tacks felt like there was enough there to go upwind, but eventually pulled out at the bottom of Archie's. Walked right up to the middle beach between the rock that was almost exposed on the outgoing tide to get a bit more of a run at it as well as clearing some kids out in the surf. I knew that there would be sand out there, so even though there were a few more rocks than normal on entry, it turned out Ok. Couple of good tacks with more pace out the back (surprising since I was expecting the NNE to make the air cleaner even on the beach), but I didn't really make too much headway. The wind dropped off 1-2 knots to make it a task even getting up on the board, so I brought it in to the beach just as Ben had arrived to set up. Ben's not having too much luck at Archie's.

I was trying to explain a technique to Ben that I'd been using in light winds to generate pace on start. I was releasing the edge and pushing out on the board to carve into a new line with more speed. It was hard to explain, but I knew I'd used the technique somewhere else. Skating? Tried to equate it to tic-tacking, but the forces applied weren't right. Surfing? Pumping a wave for speed? YES! Unfortunately Ben hadn't surfed either, but the parallels are really close.

On a wave you push down with the board while extending out your body, then compress as the board floats back up to the top of the wave before pushing hard again driving the board down. The extending and compressing keeps your head height (and body weight) about the same on the wave, but generates speed by applying more power on the down stroke to "raise" your weight (in relative terms compared to the board), then using that stored potential by dropping the weight (in relative terms compared to the board by crouching) to allow the board to float back up to the top of the wave without much power used.

In kitesurfing, the kite pulls at an angle that, when combined with gravity, makes the flat water surface act like the angled part of a wave. Pumping then works in the same way, but you don't need to keep positioning yourself back to the top of the wave as any part of the water surface will be "angled" as long as there is enough kite pull. Hmm. I wonder if this means that pumping is better with the kite lower?

It seems as I was too hasty to ditch the skate reference as it's more or less the same when pumping a halfpipe or when pumping over long distances (rather than just tic-tacking).

Archie's & Kelly's  NE ~13-16Kn (1h)
All fired up about pumping, I went out on Thursday to check out what I'd learnt. It seems that the initial pump when combined with a relatively backward kite position leads to a lot of acceleration, but continued pumps didn't feel worthwhile. I tried a couple of other techniques but didn't really achieve much past the first pump off a turn. It interesting that going over waves also forced me into a pump, but there were only a couple of times when it also resulted in acceleration.

I gave up on pumps for a bit and tacked hard upwind to up above the Kelly's flags for a little bit more practice on wave jumping. The mid-tide and moon rock positioning meant I kept out from the real shallow water, but there were still enough ramps on offer to boost off. No floaters this time, but one 2m+ jump again that I landed with speed.