I have been changing my own watch batteries for a few years now, and with good results. Of course I have no way to test them after, while I always clean the case back and the seal area and use a little silicone grease on the o-ring. I'm wondering what my chances of having a leak are. I know unless you ask or own a higher end watch, the folks usualy do not test. I have had good luck with my 50m, 100m and 200m. I do not dive only swim never go below 10 to 12 ft. I use to use a jewelery shop that had a watch guy and my Luminox leaked soon after a battery change, so Ilearned to do it myself. Juat wondering what others think.