Interesting. The manual of the Swiss Army Watch, seems to contradict some of this, at least in part. They claim that a watch rated at 50M is "suitable for showering or swimming in shallow water." Keep in mind, that it will impact your warranty a lot more than what another organization says the ratings mean. As an express guarantee by the manufacturer, they can be held to this. Full ratings for SA watches below:
- Water-resistant to 30 meters (100 feet/3 ATM). Will withstand rain or splashes of water but should not be worn while showering, swimming or diving.
- Water-tested to 50 meters (165 feet/5 ATM). Suitable for showering or swimming in shallow water.
- Water-tested to 100 meters (330 feet/10 ATM). Suitable for swimming or snorkeling.
- Water-tested to 200 meters (660 feet/20 ATM). Suitable for swimming, snorkeling or skin diving.
- Water-tested to 300 meters (990 feet/30 ATM). Suitable for swimming, snorkeling or scuba diving.