My Seiko 5 gains 20 seconds each time I swim with it; it's a brand new SKN607, received and set its time accurate to the second this past Friday.
I first noticed this on Monday when I took it for a swim, so I duplicated that workout today (500m each of front crawl, butterfly, breast + 200m back) but with a before-and-after-swim pic. (The gain seems to be exactly 20 seconds each time; I've been taking nightly pics to check the watch's precision since Friday.)
I'd like to know:
Is this normal for automatic, mechanical watches? Or
Is this just a Seiko 5 issue and not applicable to the better-made automatic watches?
Pre-swim: Atomic 14:21; Seiko 14:45; delta = 24 seconds
After 40 minutes of swimming: Atomic 56:35; Seiko 5 57:19; delta = 44 seconds