Polar Grit X – First Swim (Accuracy)

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Vantage V – Blue, Grit X – Red

Technically this is my fourth open water swim of 2020 with the Grit X, above, but let’s say it was the ‘first swim’ as it was the first time I swam with another watch at the same time.

This square image/swim was from last week and was my first one since the lakes started to re-open in the UK. My regular lake at Shepperton is not open for some reason, so it was a good time to explore and do my bit for global warming by driving further afield. This particular trip was to DIVER’S COVE in Godstone. and it was great to don my Zone3 Vanquish once again (and yes it seems ot have got smaller, must be the muscles 😉 ). A lap was something like 450m, so it is quite a small lake with a small capacity, lessened by the new restrictions. It’s quite hard to find but worth a visit as it’s quite pretty and, being a secluded, converted gravel pit, the water is clearer and warmer than elsewhere (book in advance and pay the annual membership of £20). Anyway, the somewhat jagged GPS+GALILEO track didn’t inspire me with any degree of confidence in the OWS accuracy of the Grit X and it was similar, though perhaps slightly better than I remembered the Vantage V to be.

Next time around (x3) I stayed closer to home at Liquid Leisure near Heathrow (Datchet) and that is where the first image is from of the 2x Polar comparison tracks. This is not an especially awe-inspiring place to swim but its large enough and has decent parking but that’s about it. One good thing about it that helped my comparison test is that I could swim in a reasonably straight line by following the lake bed on the Southern side of the lake.

The Polar Grit X recorded 1.990km and the Polar Vantage V (Titanium) 1.880km, which is quite a big difference and neither track looks that great, although the Grit X is the more accurate of the two.

I suspect this level of GPS performance from the Grit X means that I won’t bother to do any more OWS GPS tests with it unless GPS improvements are announced in new firmware. However, it has rekindled my interest to try out some local lakes that I haven’t been to in a while like Heron and Thorpe, so that’s a good thing.



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Thanks. But why did you use GPS + Galileo when Polar officially (on their Facebook page) recommend that europeans use GPS + Glonass for now for the best accuracy?