An autonomous device designed to guide groups of open sea swimmers, helping them stay together during training. In the often disorienting sea conditions, "Leader" serves as a visible beacon, making it easy for swimmers to follow. Each swimmer connects a component to their goggles, which vibrates to alert them if they begin to drift off course. This prompt enables swimmers to correct their direction and rejoin the group. "Leader" is built to withstand the toughest outdoor and water conditions. It features a removable rechargeable battery, two cameras (above and below the water), an inflatable part with compartments for personal accessories and water, ensuring functionality and safety during open-water swimming sessions.