Keep your phone in your pocket and your hands free—these smartwatches perform a variety of functions on your wrist. They connect to Apple and Android phones via Bluetooth, informing you when calls, texts, and other notifications arrive. Designed for harsh environments and rugged use, they meet military standards for resistance to hot and cold temperatures, shock, splashes, and submersion in up to 100 meters of water. These watches have a compass and GPS for tasks such as navigation, tracking and saving location coordinates, and calculating the area of a location by walking the perimeter. With weather and elevation monitoring, you can set the rate of barometric pressure change that will trigger a storm alert. These watches track health and fitness metrics over time, including heart rate, blood oxygen levels, and exercise. They have a solar battery in addition to a rechargeable lithium-ion one to extend the time between plug-in charging.