Simply throw the unit into the water & within seconds of immersion, it automatically inflates and stands 2m above the water. The light automatically activates, highly visible up to a mile away, even in 2 metre seas. Webbing loops allow the casualty to put their arms around the marker to help support them. When fatigued it gives them an extra sense of security & stability. Instantly deployed (can be thrown to the casualty immediately). No need to go to where a MOB unit is mounted and activate the release mechanism.