Just a word of warning to anyone who hasn't yet installed the COROS firmware updates, released on May 10 (V 3.0408.0) and May 21 (V 3.0409.0).

My recommendation would be not to update your firmware until COROS fix an issue that was introduced in V 3.0408.0 and affects the the speeds recorded when in speedsurfing mode.

The issue mainly affects the max 2s and 10s results (reporting too low) but for anyone interested, full details are available on GitHub.

logiqx.github.io/gps-details/devices/coros/smoothing/

Thanks for sharing. I noticed a 30.1 knot run on Mini Motion was recorded as 29.7 via Coros.

Wow, nice work. It makes me really glad I invested in a 255 and set it up per other instructions on these fora (multifrequency, "other," all constellations).

To show just how far all of this has come for speedsurfing, etc., it is amazing that we now consider a 0.4 kt discrepancy at 30 kt to be significant.

Long live doppler!

Select to expand quote

segler said..
To show just how far all of this has come for speedsurfing, etc., it is amazing that we now consider a 0.4 kt discrepancy at 30 kt to be significant.

Since spotting this issue, I've been making a point of comparing speeds after every run.

A difference of over a knot is now quite common on my COROS, which I think is pretty poor when it used to be comparable to the FR 255.

Ironically, I spotted the COROS issue during my ongoing trial of the FR 255.

Update 31 May: The COROS product team are now aware of the issue. The timeline for resolution is not known, just yet.

Any news on this issue?

COROS have acknowledged the issue but are yet to provide an eta for a fix.