The invention is a health monitoring system that determines the spine stress dose value for an individual on a high speed boat. The boat can produce impact injury from whole-body vibration embedded with multiple shocks. The system includes an RFID tag; a GPS; a display; a RFID reader; a multi-axis sensor unit that is an accelerometer which enables the determination of impact, vibration and shock, impact and vibration; and a central data acquisition apparatus. The apparatus includes processors in communication with the GPS, the sensor unit, and the RFID reader. The apparatus samples the RFID reader frequently, confirming the status of all individuals having RFID tags as being onboard or overboard. An application records a GPS location and time if an individual is overboard, and generates a course to the GPS location. The display illustrates a ride roughness graphically, in terms of injury potential at a particular speed and heading.