Talk:Underwater geohash achievement
A "waterproof GPS" isn't going to work so well if you mean by submerging it; microwaves and water don't mix. My recommendation would be a video of a GPS on the surface, followed by your diving (or surfacing) within reasonable range... Maybe the GPS should be waterproof, anyway, though.
Slight Question - What if the body of water is artificial (like a swimming pool or a large bath tub). Does it matter if the artificial body of water was created for the purpose of getting this achievement? ----Charlesisbozo