I wanted to open up a G-shock to adjust the time setting screw posted in an earlier thread. My watch runs a little fast. Also down the road I will have to replace the battery in about 2 years, so it will have to be opened sooner or later. My question is, on my G-shock like many others, there are 4 screws holding the back on, one on each corner. If I take the back plate off and put it back on, will the watch still be WR to 200 meters? Even though I will snug the screws down as much as I can, I'm afraid it won't seal as good as when it left the factory? All those people who have taken off the back plate to change a battery, etc... is the watch still o.k. under water? Thanks.