Apple Watch Ultra Location for Open Water Swim Wrong

[Slartibart]

to add to @Significant1: sea water has a conductivity of 5 S/m. GPS has a frequency of around 1.3 GHZ. So a GPS signal has a “skin depth” of 6 mm. That means that the signal loses 36.7% of it’s amplitude after only 6 mm; it is reduced to 1% of its amplitude after only 2.87 cm.

Fresh water has a conductivity of 0.005 S/m, resulting in a “skin depth” of GPS of about 20 cm; the amplitude is reduced to 1% after 90 cm.

People have tried for example the GPS of Go Pros under water - till 10 cm salt water depth it becomes progressively significant inaccurate. Below 10 cm in the sea you don’t have to bother 🤓

TL;DR: Apple Support has informed you correctly: frontal crawl it is.

nota bene: the GPS of the Apple Watch Ultra might work well if you wear it while floating on your back… stretch out flat on the surface… dorsa manus up… maybe here. 😁

 

[debsagos]

If Apple already explained why you're watch isn't recording your swim workout and that there's no way around it, seems you already have your answer..

The thing is it IS recording the route. It is visible in the data sources part of my Health App. Apple are investigating as they we baffled as to why it IS recording, but not in the right place.

 

[Slartibart]

The thing is it IS recording the route. It is visible in the data sources part of my Health App. Apple are investigating as they we baffled as to why it IS recording, but not in the right place.

my educated guess: the tracking is simply not sufficient accurate to calculate a SWOLF score, pace, etc. Workouts are not necessarily just about the route, are they? Btw. how accurate is the route?

 

[debsagos]

my educated guess: the tracking is simply not sufficient accurate to calculate a SWOLF score, pace, etc. Workouts are not necessarily just about the route, are they? Btw. how accurate is the route?

Roughly accurate. You are right, it may not be accurate enough to calculate all the other stuff. It's just a bit disappointing as I didn't realise I could not use it for non front crawl swims.

 

[jz0309]

The thing is it IS recording the route. It is visible in the data sources part of my Health App. Apple are investigating as they we baffled as to why it IS recording, but not in the right place.

please keep us posted on their response (if you ever get one )

 

[Howard2k]

Roughly accurate. You are right, it may not be accurate enough to calculate all the other stuff. It's just a bit disappointing as I didn't realise I could not use it for non front crawl swims.

Reading a couple of reviews that seems to be a common issue with open water swimming.

Openwater Swim GPS Test Extravaganza Results

A few years back I took a week while warm-water swimming to test a slate of GPS watches in openwater. Like a race, each watch got essentially one go at it, competing against another watch on the other wrist –

www.dcrainmaker.com

 

[debsagos]

Apple have been in touch, and are also slightly baffled. They are going to install a tool on my phone to capture the activity logs and to see why it won't link up the route and the workout (though I'm thinking I have my answer from this forum already).

 

[Spindel]

PROBLEM SOLVED (well, no......as it's unsolvable):

Spoke to Apple, and the problem is that Apple watches are unable to GPS track outdoor swims IF USING BREASTSTROKE. They ONLY track freestyle stroke.

I'm baffled. Especially as the route IS recording in the Workout Route Data Sources.

If I had seen this thread earlier I could have told you this.

Water isolates RF signals very effectivley and the GPS signals are weak. When the watch is submerged it can’t get a connection. That’s why it works poorly with breast stroke but OK with crawl, back stroke and butterfly stroke since you lift your hands out of the water.

I usually lift my watch arm above the surface for a couple of seconds now and then when swimming.

I noticed this the first time I swam with my AW6.

If you also have LTE enabled in the watch you’ll notice high battery drain while swimming since the watch tried to contact (and fails) the cell tower while submerged.

 

[Can Inelli]

Apple Watch Ultra is terrible with open water swimming. At least some units I assume are faulty. I bought the AWU the day it came out. I swim every single day throughout the year, at least 1-2 kilometers. Before AWU I used to have Series 7 LTE and it worked perfectly. AWU records bad gps points and records extra distances I would say 80% of the time. I had 20+ calls with Apple support since months, tried everything, they even connected remotely to my device to check but no issue has been found. I have been asking for a replacement but they are insisting on me sending out the watch for service for 2-3 weeks. It's really crazy. A friend also has an AWU, we swim together, his device functions perfectly.

I posted on a lot of forums about this. It's been driving me crazy and Apple's support has been absolutely terrible. They are not giving me a replacement.

fyi: I swim freestyle.

Check this out: https://forums.macrumors.com/thread...swim-wrong-distance-faulty-gps-track.2395116/