While the eTrex unit is quite rugged, my biggest fear has always been of the screen getting scratched. Also I noticed that if you use a handle bar mount (see my other instructable) like the one I made, vibrations may cause the mount to rub against the body of the eTrex and cause scratch marks. ( I like my gadgets new and shiny :-) )
Step 1: The Materials
2. A scissor
I used a 1.5Litre bottle of Coke as shown in the picture, the important thing to remember here is that the circumference of the bottle (measured around the lable) should be identical to the circumference of the eTrex measured along the length/vertically.
This will be more clear as we go along once you understand what it is I am trying to do....
Hope you have finished drinking that bottle by now because you need to empty it, wash it and dry it for the next step. Burp...
Step 2: Preparing the bottle
Now poke the scissor into the bottle carefully and start cutting it so that you are left with the transparent cylindrical portion of the bottle as shown in the picture.
Since I don't yet have a good camera and the bottle is transparent anyway, I will try and explain with the help of hand drawn diagrams.