MARA is a water-tight processor that fits on the diver’s mask near the ear. Upon entering the water, sensors on MARA detect the change in resistance and activate the unit. Once active, MARA calculates the depth based on water pressure. If the diver begins ascending too quickly, audible tones are sent from the unit to the diver’s ear.

MARA can inform the diver if they are ascending at 30, 40, 50, or 60 feet. The tool also signals a safety stop at 15 feet of water, as recommended by most dive training agencies around the world.