I had a nice sail yesterday - my first sail since April with my GPS (garmin foretrex 201).

After the sail, I noticed water in my GPS - it seems to be under the screen - a bubble of water. If I push the screen, the bubble moves/expands. I managed to download the track to my computer without any problems - and the track was without error.

I LOVE my garmin - I need it for race starts and the tracking quality is more than I need - great for reflecting on races at the days end.

Any thoughts on whether this water will effect its performance? Will I need to replace it?

Sorry yes. Killed 2 this way. Stick it in a bag or case

I have the same problem from a leaking bag. Dried out in sun for ages. Still works fine but the water is still between the screens (I think).
Kato is right, without a good bag it will die.
Must update to a Gt-31.