Since there hasn't been any wind recently, I decided to write a guide about GPS devices and focusing on speed sailing. I had the idea about a year ago but I never seemed to have the time or inclination to write it until now. ;)

It covers a mixture of topics, some of which are listed below:
- Basic principals and common misconceptions
- Device comparisons (features, pros and cons)
- Appendices: Doppler, spikes, grid effect, etc.
- Glossary of GPS terms

Hopefully some of you will find it interesting or useful. Any feedback welcome!
Nice work! looks pretty complete.
Thanks. It would be nice to add the other "supported" devices too (e.g. Geko and Edge) but I don't have any personal experience of them. Any additional information welcome!
How about putting in a note about the Garmin Forerunner 310XT not having the ability to record trackpoints at 1 second intervals?  Even though it's an option in the 305, it's not on the 310.  This is something they could easily fix in a firmware update, but they aren't inclined to do so.    Having it written up in as many places as possible might motivate them. 

Yes, that is a very good idea.

There is obviously a difference between an "approved" device and a "potentially suitable" device for speed sailing but it will be helpful to list devices that are definitely a waste of time.

I've had a quick look at some of the manuals (re: models not mentioned in my guide) on the Garmin site.

Forerunner 205, 305 - 1 sec
Edge 205, 305, 605, 705 - 1 sec

Forerunner 310XT, 405, 405CX - only auto... it says "approximately 4 seconds"
Foretrex 301, 401 - manual does not say what is available in "track preferences" so I cannot tell

I'll have a look at a few other models and make some additions to my guide.
Great help for a spanner man like me...but I had convinced myself that Pete Young's Gt-31 read higher than mine!
One useful feature of the Garmin Foretrex 201 to display your position as an OS grid reference. Very useful when walking or cycling in the New Forest, but nothing to do with speed sailing!
I have added a heap of Garmin devices to my guide so it now covers all of the models from the common ranges. Hopefully it is still relatively easy for people to digest!

I don't have any hands-on experience of the eTrex H range (high sensitivity models) so I have had to rely on the manuals for that information. The same is true for the Foretrex 301 and 401 so any further information could be helpful.

Warren: I've also listed some Garmin devices which should be avoided and why (including the 310XT).

Version 2.0 of my guide is at the same URL:

I've made a few minor refinements to the guide (issue 2.2) and uploaded to the original URL.

As always, please let me know if anything needs further work.

I put a GT-31 and Forerunner 310XT in my cr and drove around. max speed, 10 sec speeds etc were within 0.1 to 0.2% of each other. The faster you go the 310XT seems to reduce its sampling interval.
Why not put this on the web? Nice info!

If you need any help let me know. Niels.vanderbeek(at)gmail.c0m

A web page would be better to read and comment than a PDF...
great document!!! I can publish it under FAQ on this site, it would be of great value for all of us! Of course I will mention your name.

what is your opinion on this?