GPS has the reputation amongst the general public of being incredibly accurate - after all, it can pinpoint your position anywhere on the planet. But is it really that accurate? How useful is it in rowing? How does it compare to the more accepted impeller on the NK SpeedCoach, in terms of accuracy, and general features for coaches? How useful is it for laying out a course?
If you patrol the various message boards for rowers you will quickly see some of the benefits of GPS - the units record every second of the workout for later downloading, velocity and distance measurements are available without adding a speed coach to the boat, no impeller is required on the hull, measurements are relative to land so distances are not affected by currents. On the other hand, you will also see many criticisms, most notably that the GPS is in fact not all that accurate (up to 15 m off for a single position), it ONLY records every second so changes within a single stroke can't be seen, it does not measure relative to water so velocity measurements will be affected by currents and more. We will examine these in some detail during this series of posts.
I was kindly given an 2005 Nielsen Kellerman (NK) catalogue by reader Frank Biller who is the Nielsen Kellerman Head of World Sales for watersports and timing instruments. This catalogue included a paper by Dr. Volker Nolte comparing GPS with the NK impeller. Dr. Nolte most of you will know as the editor of Rowing Faster; he is one of the most well-respected experts on the biomechanics of rowing. The findings in this paper will be presented in one of the next posts in this series.
Mr. Biller was also kind enough on behalf of NK to do a brief interview about why they don't currently use GPS in their systems, and the possibility of using it in the future. Look for the interview in another upcoming post.
Finally, In2Rowing is developing an alternative to the NK Cox Box that has GPS built in. It looks like an intriguing product. It includes 256 MB of memory to record workouts that can later be downloaded and overlaid on Google Earth Maps! I have invited them to do an interview as well for publication. I hope to have something soon, but will present something on this product regardless soon as well.
There is much to examine in this series, and along the way I will include a few other topics that come up so that those of you who are not excited about GPS have something to look forward to as well. In the meantime who out there has tried GPS in a boat? Are there any heavy users of the SpeedCoach who may have innovative ways of using it?
Please share your experiences with us in the comments or e-mail me.