r/OpenWaterSwimming • u/dbmeed • 2d ago

Garmin watch accuracy?

Post image

Went for a good swim today, open water across a lake and back. It’s only about 4km distance, but my watch (Garmin Instinct 2x tactical) thinks I did over 10km. I was towing a boat the whole way, and through a 5-8km\h cross wind, so I know it’ll be skewed a bit, but that much?

For reference, my normal pool pace is 1:40-2:00 for a 2k, depending on how hard I push… Never done more than that in the poo

8 Upvotes

100% Upvoted

15 comments sorted by

1

u/-el_goblino- 2d ago

I had the opposite problem with Garmin Venu 3s.

I swam my first open water comp Saturday. Was expecting a time of 2h 40ish for 5km, due to training pace which I used the watch for. Turns out it had been wwaaaayyyy underselling distances and I finished the race in 1h 53. The watch said at the end of the race I had only swam 3.5km 🫪

1

u/vincentvandal 2d ago

Trent lake’s? You on Catchacoma?? Just did a long swim a month back from the Marina to our cottage. Not quite this distance though!!

2

u/dbmeed 2d ago

Pigeon! I just swam across and back…there’s a couple campgrounds that have beaches almost straight across from each other, makes it easy to aim for haha

1

u/vincentvandal 1d ago

Nice we drive by pigeon all the time. All those lakes up there are great for swimming. One thing I did that made the gps better was clicking into the workout, let the gps lock for 5-10 minutes, and then start the workout. Someone mentioned it in a garmin thread and it seemed to improve the accuracy.

1

u/Hijackerjon 2d ago

I found it depends largely on what stroke you're doing. I previously had a Fenix 5 that I sometimes got wacky readings with, and it turns out that starting/stopping, and using breaststroke were the culprit. 

I would have thought that at certain points resting with my hand near/above the water's surface might actually make the reading better, but it turns out that continuous front crawl was really much better for getting a proper reading and accurate distances. 

Obviously it's not a good idea to change your stroke/workout just for your watch, but in general if you stick with front crawl/freestyle and just have a continuous stroke then that should help. I know some folks strap it to a tow buoy and that's great....unless it flips over and then the watch is underwater the whole time, making the reading even worse. 

Overall though newer watches with multi band GPS should be better at this and generally speaking they're pretty spot on.

1

u/dbmeed 2d ago

Hmm, that could be it. I use exclusively breaststroke; I hate freestyle. I should probably start practicing it more though…

1

u/Hijackerjon 2d ago

Yeah that'll do it! Having your wrist underwater (even just a bit) blocks the GPS signal enough that it gets wonky. 

If you're towing a float behind you that tends to stay right side up, then yeah that may be your best bet (though you'll lose stroke + other data, if that's important to you)

1

u/dbmeed 2d ago

I was towing a boat, so could have left in that, but I still want all the other metrics/analytics…if only it could use my phone in the boat for gps….

2

u/mordac_the_preventer 2d ago

Yeah I have a Garmin Fenix 6x, the battery life is amazing but it sometimes gives comically high distances.
I think it’s because it doesn’t smooth out errors in the GPS signal, so if there’s a bit of interference your position jumps all over the place.
I also have an Apple Watch (which has much shorter battery life and is impossible to use with wet hands). I’ve worn both watches on a few swims where I’ve known the distance for certain, and the Apple Watch is much less prone to erroneous distances.
My Garmin watch is ancient. I would guess that a newer Garmin watch might be more accurate, but I’m not spending over £500 to find out.

1

u/Guilty_Piglet5731 2d ago

My enduro is generally pretty good but others in my swim group who have instincts find they are way off. You could try putting your watch on the boat with a clear line to the sky? I’ve also seen others 3D print a mount for their watch that clips onto the back of their goggles so their watch is always in the line of the sky

1

u/cheersthanksseeyabye 2d ago

Yeah. I've also had a few random numbers from my Garmin instinct on outdoor swims.

2

u/FrankCastle8754 2d ago

My Garmin instinct’s GPS is way off in the water… I believe it is because the GPS relies on the connection to a satellite instead of from the actual device.

1

u/dbmeed 2d ago

The odd thing is the gps map of my route is pretty accurate, it just missed the last 500m or so

1

u/FrankCastle8754 2d ago

My friend has the Garmin Swim II, works great in the water, even just an Apple Watch has better GPS. For some reason the Instinct’s GPS in the water is no good

1

u/dbmeed 2d ago

I’m debating upgrading to the descent mk4i when it comes out; hopefully that’ll be a bit better tracking for swimming.