Waterproof - Water Resistant - See Information For Definitions
None of the stopwatches in our range are waterproof to the extent that they can safely be operated under water. To our knowledge, such a stopwatch does not exist outside the realm of divers' watches. We have tried operating some of our professional stopwatches under (shallow) water, and some of them do seem to work, but each time a button is pressed, it breaks the seal to the inside of the stopwatch which allows water in. So we don't recommend that our watches are operated underwater.
There is confusion around the definitions of 'waterproof', 'water resistant' and 'splash resistant'. We therefore use the industry standard "IPX" where IPX0 is not water resistant at all and IPX8 where the device is protected to a depth of more than 1 metre. The Fastime 28LW stopwatch is water resistant to IPX7.
Here are the basic definitions:

