My son bought the Instinct 2 Surf Edition a week ago. It seemed to work perfectly well until he updated the software. The battery will now not last more than 11 hours.
We've tried all the Factory Resets, Hard Resets etc. I am sure it is a software issue that everyone is facing as it seems to have only occurred since the 14.12 software install.
@Garmin could you please check and test software before releasing. The watch is now pretty useless as we can't do anything with it at this stage.