After looking at my bikes GPS (Garmin edge 200) it looks like it will fit perfectly onto my bar. Even though it has a high enough waterproof rating i still dont think it would enjoy getting slammed onto water at high speed.
it got me thinking that even after having a hard stack at high speed does a bar ever get immersed in water given that it shoots up to its depower position very quickly?
In large surf its a different story, anyone have any tips for GPS locations?
Best place is in a 'soft drycase' strapped on your upper arm I reckon - I'm now using my iphone and using kitetracker. In its waterproof pouch it floats in the event that it might become detachted from me 
This is the one I use - H2O Audio Amphibx Fit Waterproof Armband for iPhone - (previously I had use my garmin etrex again in a 'soft' waterproof case strapped to my thigh when I had a dabble at speed sailing
