Abstract: A user-programmable, submersible actuator apparatus that includes an inflator mechanism configured when operatively connected to an inflation source and to an inflatable device to provide command-activated release of fluid from the inflation source to the inflatable device and thereby provide a buoyant force. A controller causes the inflator mechanism to actuate inflation in the event of the first of a deep submersion condition or a heavy bobbing condition. The deep submersion condition may be determined when a specific (approximated) submersion depth has been detected. The heavy bobbing condition may be determined by a predetermined number of bobs of a specific (approximated) depth (less than the deep submersion depth) being detected or by a predetermined frequency of bobbing being detected. The water sensor mechanism may include a pair of sensor elements, having outer ends each recessed in 0.9 to 1.1 mm, or 1.0 mm.