For purely cardio, fitness or cross-training workouts, an entry-level watch model will provide you with the essential features: heart rate, time, stopwatch, and target zone for optimal caloric output. If you are a steady runner or compete in triathlons, opt for a multisport GPS watch. It incorporates all the previously mentioned features as well as target training zone indicators, countdown timers for interval training, and you can go from one sport to another with just the push of a button. A GPS watch equipped with an altimeter and barometer is your choice companion for walking, trail running, navigation, and any other orienteering activity. Choose models that come with map packs suited to your activities and needs. All the watches are moisture, sweat and splash resistant, but for swimming and diving, opt for a certified water-resistant model. Please note that the depth generally indicated by manufacturers does not take into account the additional pressure caused by movement. In consequence, you will need a minimum of 50 m water resistance for swimming and 100 m (10 ATM) for diving.