Jack-up rigs are similar to drilling barges, with one difference. Once a jack-up rig is towed to the drilling site, three or four ‘legs’ are lowered until they rest on the sea bottom. This allows the working platform to rest above the surface of the water, as opposed to a floating barge. However, jack-up rigs are suitable for shallower waters, as extending these legs down too deeply would be impractical. These rigs are typically safer to operate than drilling barges, as their working platform is elevated above the water level.