Don't expect a watch w/ a 5-10m rating to be any good for anything but washing your hands. The meters rated on a watch aren't the actual depths you can reach. For serious scuba diving most mfrs. will recommend 50bar+, which is 500 meters. But you're not actually diving to 500m. I mean you could, but that would probably be curtains for you.
Plus in many watches the rating has more to do w/ pressure resistance. If I remember correctly, ORIS used to have a good write up on their site regarding their watch ratings. Breitling used to as well but I haven't been able to find it. I'm sure other dive watch mfrs. have something similar.