Here is an explanation of what different IP ratings mean for watches. Most watches we sell will be either IP65 or IP66. Some are starting to be IP67 which makes them great for continued use in water.
This table describes the official level of protection provided.
IP65
Protected from low-pressure water jets from any direction.
IP66
Protected from high-pressure water jets from any direction.
IP67
Protected from immersion between 15 centimeters and 1 meter in depth.
IP68
Protected from long-term immersion up to a specified pressure.