Scuba diving is a mind-blowing experience, but divers know just how easy it is to become disoriented, underscoring the importance of a good dive computer. Garmin’s Descent MK1 is its first GPS-enabled dive watch. It has a three-axis compass and in-dive data, as well as monitoring heart rate and up to six gases. The battery can live for 19 days in watch mode and 40 hours in dive mode. Underwater exploration will be significantly safer with this around your wrist.