Wednesday, September 30, 2009

Tracking windsurf sessions

Earlier this year, I started logging my windsurf sessions in a little database. Here's a screen shot of a session record:




You can click on the image to see the full size version, but I'll explain the various parts below.


The top left section contain information about the session - where, which gear I used, wind speed, some data from the GPS, and comments.

In this session, I was going for speed and worked on small board jibes. I managed to set a speed record for the board I was using, as well as a jibe record. The "40%" for the jibe means that the minimum speed was 40% of the entry speed; 40% mean I nicely planed through the jibe, but there was room left for improvement.



In the bottom left section is a screen shot from iWindsurf.com that shows the wind for the day. Great day, except that I waited too long before using the Mistral Screamer, our fastest board. Since my lively wife was having too much fun on the Screamer, it was 5:30 or so before I used it, and the wind had gone down a bit by then, both the averages and the lulls. Had I tried an hour earlier, I probably would have set more records.



The top right section has a screen shot of a speed graph, generated with GPS Action Replay. It gives me a quick overview of how the session was - I was planing nicely most of the time. The dips also show me how my jibes were - mostly dry, with a few good ones in between.

The bottom right shows the tracks for the day. They are color-coded for speed; I set the units to mp/h instead of km/h for this image. The blue arrow in the middle shows my personal speed strip for the day - a shallow area behind a little gras island, where the water was nice and flat.
This was the first time I sailed on this side of PowderPoint bridge in Duxbury, and I really liked it - great for northerl winds, where the bridge creates to much wind shadow on the other side.

Tools Used
Here's a quick overview of what I used here:
  • iWindsurf.com for wind forecasts and graphs
  • Navi GT-31 GPS (my best birthday present ever!)
  • GPS Action Replay Pro to analyze and plot the GPS data
  • FileMaker 10 to create the database (I used FileMaker since I had it on my computer; this could probably be done as easily with Bento or something similar)
  • A MacBook Pro running OS X 10.5
I'm also posting my sessions to gps-speedsurfing.com - keeps me humble after I thought I was soooo fast. But then, most serious posters there use dedicated speed equipment, while I'm usually on a 120l board with padded deck that I had bought for my 12-year old daugther a few years back.