Just thought i'd share this to see if people have had better luck with their GPS or have had similar problems to me. Running I run a 5k every week and know the route extremely well. I usually take my phone and use Runkeeper, with it giving me audio cues every 500m. Because of this, i know pretty much exactly where each .5k point is on the route - the Apple Watch was inaccurate right from the beginning. I left my phone at home and the disconnected from phone icon was showing at the top. I had the watch track my walk to the start point in the hope that this would give it time to get a GPS lock. As you can see from the screenshot of the walk, it appears to have done so part of the way into my walk... http://imgur.com/XLAxLd4 However, once i started my run soon afterwards, it failed to get a GPS for the first section and just assumes i ran in a straight line from roughly where i started to when it got its first GPS lock. This suggests ending an activity (as i did with my walk to the start point) causes the watch to completely start from scratch when finding a GPS signal again - incredibly annoying as there is no cue for the user to let you know when it has GPS and has stopped guesstimating from the accelerometer. It should be noted that i run 2.5km and then double back on myself, hence the two lines. The line from the green pin is the start of my run - to my eternal shame i walked the last 1km back as i've had a few weeks not running and it was horrendously hot; this may have helped the GPS, as it certainly had a better lock on the way back. http://imgur.com/QFTz3VW Throughout the route, it sporadically lost GPS signal, each time making the timings and distance less accurate. This could be due to trees etc., it's hard to say. http://imgur.com/UkveaiE This route is on Hong Kong island so it's on the side of a hill and has some trees occasionally blocking line-of-sight to the sky, but on my phone it generally hasn't caused a problem - as can be seen here from a Runkeeper screenshot of a far more successful run. http://imgur.com/ZEH6MoE I'm borrowing a Garmin 920XT from a friend, so on my next run i'll wear both and compare. Swimming This was far better. In swim mode i did 40 lengths of a 25m pool. I noticed that if you raise your wrist to wake the screen when out the water, the screen comes on and shows your stats, but the same movement underwater does not. Pressing either of the physical buttons brought up the screen and allowed me to check how many lengths. There was a slight issue with it always being one lap behind, i assume because it thought i hadn't finished the previous lap (maybe it waits for a sudden movement in the other direction before recognising the lap has changed) so i had to mentally add one to the lap count each time i checked. When i'd finished my 40th and final lap, the screen said '39' but when i ended activity it changed the counter to 40 (i guess recognising that final lap must have been finished).