Not recording number of lengths correctly

Hi all. Since getting my Swim 2 in Dec, I don’t think I’ve ever had a week where it 100% recorded lengths correctly.  Was usually the first swim of the week on a Monday that would be a bit glitchy but remaining swims in the week usually (about 90%)  ok.  I put it down to my poor technique.  This week, since the last update though not one swim has recorded correctly - yesterday for example I swam 2250m and it only recorded 1850, so dropping out about 50m every 500m interval. I am just swimming front crawl in a 25m pool, no tumble turn.  Is it all due to my techinque?  I always try to push off strong at each turn.  

I did find during some swims that it would have gone wrong, but a length or two later would have fixed itself - how does it do that?  I thought that if your SWOLF suddenly went from say 56 to over 100 it would realise something was wrong and try to fix, or am I wrong with that?

Anyway, does anyone have advice or is anyone experiencing the same since last update?

  • I swam only 4 times with Swim 2, but for my swimming (mostly freestyle, only a few lengths drill and breaststroke) the number of lengths is always spot on. This is the only metric that is really accurate, as accurate as with the old Garmin Swim Smiley

    Both flip turn and open turn are detected pretty good.

    My experience of the past 6y with Garmin Swim (1) is (and the same seems to be valid for Swim 2), that usually only one thing pretty sure disturbs the lengths count: not swimming at a constant pace. Strong deceleration followed by a strong acceleration in the middle of the lane counts like a turn. For example you have to stop, because somebody is in front of you and than start again swimming. This is like a push off. Or something like 15m slow + 10m sprint.

    This probably explains your magical fix during swimming. One missed lap/turn has been compensated by a turn, that actually was only a strong acceleration in the middle of the lane.

    I think, you could pretty easy find out, if your turn technique is good enough for Swim 2 or not ;) Just swim a lot of 50m intervals (in a 25m pool -> always 1 turn / interval) and while resting check the number of lengths. Something like 20 x 50m @ your 100m pace, 15s rest. You can configure the swim widget to see everything relevant (interval time, rest time, interval distance) on the first screen. Like this you don't waste time and can find out pretty easy, if it's your turn technique. And if yes, how does it feel, when it's wrong.

  • Thanks for your feedback.

    However, your explantion above would mean that it would record more lengths than I'm actually doing and not fewer.

    Again tonight it was innaccurate.  For the first 2 400 intervals it skipped the length after 175m and I had to do a  "false start" to get it to recalibrate.  In my next 2 400m intervals it was all over the place.  I don't change my pace dramatically mid-length.  I'm not a particularly fast swimmer - average around 2:40 per 100m.  Below was my app reading for the session.

    Anyway, not sure what to try next.  It's a bit disappointing.  I'm trying to get my time down to 2:30 per 100m, but as I don't have confidence things are recording properly, I'll don't think I'll ever get a clean reading.  Thanks for your suggestions though.  I'll try the thing with the turns next time I'm in the water.

  • If my interpretation of your data for the 1st 400m interval is correct, than the turn between length 10 and 11 didn't count. Maybe something there was different than on the other turns: you looked at the watch (and the hand/arm movement was not the expected pattern), the turn was too slow (too mach gliding at the end of the length + slow push off), ...

    Similar behaviour during the 2nd interval.

    One question: Did you enabled the auto rest options? At least your screenshot looks for me, like the auto rest is enabled and it doesn't do a good job. If it's enabled, just disable it. I think, this could improve the lengths count. Some reviews say, the auto rest feature is ok (in some conditions). I'm pretty sceptical. I always try not to use more features than strictly necessary.

  • Wow! That's great, is this site managed by you ? Can you make a sticky post with this URL?  I fixed my swim session today with 2 broken laps (one split and one merge) without having to check the help page for the tool, very intuitive . Well done! (I'm going to send a small donation for this tool)

    Have a nice day!

  • I do not manage this/that site, and as the tool is not created by Garmin, I doubt that they will put it in a sticky post.

    There is an old topic about the tool

    forums.garmin.com/.../edit-you-garmin-swim-data-free-online

  • Unfortunately counting is done with simple accelerometers, which are prone to disruption with any change in movement (either intentional like a turn or unintentional), and sometimes are not sensitive enough (e.g., slow push off, not gliding etc.). I have found my watches to be consistently accurate as long as I adapt to them. Regular stroke, firm push off, 1 or 2 sec glide with kick out, taking first stroke with the arm the watch is on (but try a different arm) and not speeding up or slowing down or changing stroke mid lap all help. I would say >95% of the time it is spot on, and typically I know when I cause a miscount (e.g., passing someone, hitting the lane line or a swimmers wrist), and can see it in the lap times (an extra long or short lap). I wish they let us determine a minimum and maximum time to count as a lap to help prevent this. All said, I always count laps mentally as well and the watch is just for timing and confirmation, and occasional reminder if I get distracted and lose count on long intervals. Technology is great, but nothing is perfect.

  • Thanks for this - I’ll give it a try....

  • Thanks for this feedback.  Might try the watch on other wrist tomorrow to see if that makes any difference and will take more care on turns to see if it’s my technique that’s causing the issues. 

  • Just to let you know I concentrated on my turns today and tried to execute as you describe and BOOM, not one missed length out of 100 lengths!!  Thanks very much for the tips.  Didn’t need to try watch on different arm.  It was probably my technique (or lack thereof) all along.