The SP1 wrist computer is specifically designed for freediving and spearfishing. In addition to a Dive Mode, the SP1 features all of the functions of a modern digital watch (time, date, chronograph, countdown timer, daily alarm, dual time). The Dive mode activates automatically with water contact and resumes watch function automatically 30 seconds after exit from the water. During the dive, the display shows in real time: Depth, dive time and water temperature. Once on the surface, the SP1 automatically shows the surface time and last dive time. The SP1 records up to 200 dives. The data stored for each single dive is: Sequence number of the dive, date and time, water temperature, duration of the dive and maximum depth. We highly recommend that battery replacements are performed by a certified Sporasub dealer to ensure it is waterproof and to maintain the warranty.