I've seen and heard a lot of discussion about watches and the water resistance/water proof issue. Here's my 2 cents- hope it helps someone!! :)

A lot of people are either uninformed, or misinformed of what these "ratings" really mean. These figures ARE NOT literal valuations!!! You CANNOT go diving to 100ft. depth (44 psi) with a 3ATM-rated watch and expect it to survive- period. Well, you COULD, but not if you want the watch to actually survive and do it's "watchy" thing! ;)

ATM stands for Atmosphere and each ATM= 10 meters= 33 feet. *There is 4.4 pounds per square inch (psi-) exerted for every 10 meters of water depth. These ratings are also based upon tests performed in a lab (i.e., controlled) setting and is only for GRADUAL IMMERSION in STILL waters for a very limited period of time- usually just a few minutes!!

3ATM (30 meters= ~100 ft.): This is the initial level of protection/water resistance. This is the basic standard to which the majority of watches sold today are built, both high-end and low-cost watches (there are real cheapies that don't even have this, but they are not a subject of this guide). I wouldn’t even think of purposely immersing a watch with this rating for any period of time. Try to cover it up in the rain. If you get it wet, dry it off ASAP. NO SHOWERS and NO SWIMMING! *There have been so many times I've heard of someone taking a 3ATM watch swimming and hearing them complain about "moisture under the crystal", or that the watch stopped working altogether!

5ATM (50 meters= ~165ft.): Walk through the rain ;), don’t worry too much about getting it wet while washing your hands or in everyday endeavors, but dry fairly quickly. Try NOT to go swimming! Beware of taking a shower with this watch on....Dry as soon as you can!!

10ATM (100 meters= 330ft.): Light swimming MAY be OK- POOL ONLY. However, IMHO, you're still taking quite a chance doing this with most watches. Salt water is a whole different animal when it comes to cleaning and length of time in water. NO depth, or pressure. Shower should be OK, washing hands and getting watch wet USUALLY OK. Of course, dry as soon as you can.

20ATM (200 meters= 660ft.): OK to swim and OK to snorkel- NO DIVING to any real depth. THIS is MY basic level/requirement before I really feel confident about testing a watches seal integrity or Water Resistance. 

Any rating higher than 20ATM and you'd better be getting a really great watch that is backed up by a matching equally great warranty. **You’ll also most likely pay a good deal more for these watches, because they’ll be considered Professional Diving watches. Even though I'm not a professional diver, I have a few watches with this rating, because, well...they look Great!! ;)

Remember, we're talking water "Resistance"- NOT Water Proof!! That term has not even been allowed on watches for many years.

***Now, you can get a GREAT Low Cost watch that just happened to be built really well and will perform higher than it's basic 3ATM (OR LOWER...;) rating, and that’s great!! Have at it! They are very cost-effective and that's why they're called "beaters"! ;) But, remember there are also watches that will NOT live up to the higher ratings!!

IN MOST CASES, you should go by these guidelines to help protect your watch investment, whether it’s $100.00 or $1,000.00+, or $9.95 (or even less!) from one of the Deep Discount Volume Retail Chains.

Hope this helps! Any questions, let me know! Questions, comments, clarifications are welcome and encouraged!!

Regards, Drew