View Full Version : Re: validity of boat velocity measurements

11-30-2009, 06:33 AM

I believe most auto magazines and auto manufacturers use VBox made by
Racelogic for car performance data acquisition. Their devices log data at
5-100 hz.



The VBOX II SX5 samples at 5hz and retails for 1600 (~$2600). Listing on

The VBOX IISX is a powerful instrument used for measuring the speed and
> position of a moving vehicle at 20Hz. It is based on a new generation of
> high performance satellite receivers, and will measure acceleration figures,
> braking distances, lap times, cornering forces and much more. Due to the
> small size and simple installation procedure, the VBOX is ideally suited for
> use in cars, bikes, off road vehicles and *boats*.

Hope this helps.

Dat Phan
MS Student, Kinesiology
San Francisco State University

On Wed, Nov 18, 2009 at 10:32 PM, Lisa McDonnell

> I'm interested in devices used to measure boat velocity (ie: sprint kayak)
> accurately... given flat-water conditions, little wind etc. It's important
> that we reach a high level of precision and interested in calculated stroke
> to stroke boat velocity (takes approx. 0.4 - 0.6 seconds for a single sided
> stroke) when determining performance variables.
> I have considered impellers with a velocity sensor made by NK used for
> Rowing, but have also heard that there are high frequency GPS systems that
> exist and sample at 4 Hz? Can anyone suggest a product, or know the
> approximate cost of such a GPS device? Or are there any other devices that
> can measure stroke to stroke boat velocity?
> Thanks,
> Lisa McDonnell
> PhD Student
> Institute of Sport and Recreation Research New Zealand
> School of Sport and Recreation
> AUT University
> ---------------------------------------------------------------
> Information about BIOMCH-L: http://www.Biomch-L.org
> Archives: http://listserv.surfnet.nl/archives/Biomch-L.html
> ---------------------------------------------------------------