I bought a G-Shock GW-2310 (second hand) and have been wearing it for the past few weeks and been loving it, has been dunked in water and generally treated the same as my ancient Timex Ironman was - apart from it has been exposed to sunlight slightly more often to keep it charged- and hasn't yet been swimming with me...only through pure fluke rather than choice
Anyway today I glanced at my watch at lunchtime - all was OK and a couple of hours later I took another glance to see if it was hometime yet and the face was all fogged up!
As soon as I came home I took the rear of the case off - and it doesn't have its O ring/seal!
I can see the recess it would have sat in...but it definitely is not there!
(very good job I didn't take it swimming then! as I often dive to the bottom of the pool)
I have been searching for a replacement seal but not found any yet
I have emailed Casio UK (because I'm in the UK) but I don't suspect I will hear back for some time
I have found a company in the UK (online) with some interesting looking G-shock parts and have emailed them to see if they can help
The back is off the watch and I will keep somewhere warm to see if I can remove the moisture before it causes any damage
Fingers crossed I can find a suitable seal as I have really warmed to the G-Shock