fire_diver
Contributor
grassyknoll:Hmmm....geocacheing has gotten popular. Anyone heard of scuba geocacheing? Might be a bit tough to get GPS coordinates but think of the fun you could have leaving some interesting items for someone to find. A slate to record who's been there and comments. Maybe even an UNO deck or Battleship game.
If all else fails, your in a lake, go negative and practice making mud-angels on the bottom.
The guys at LakeDiver.com like to take lakediver merchandise like signs, license plate frames, etc. and hang them on tree branches and such.