The Mackereth corer (Mackereth, 1958; Smith, 1959) is a pneumatic device that consists of a cylindrical aluminum chamber ~1.2m long and 0.5m in diameter. A pair of 6m core barrel tubes, one of smaller diameter and nested inside the other, is inserted into one end of the chamber and protrudes from its top during deployment. The apparatus is lowered to the lake floor on a rope, and air hoses connect the chamber to the vessel at the water surface. Compressed air is used to pump the water out of the chamber and then to force the inner core barrel downward through the chamber and into the sediment. The chamber then fills with compressed air, which increases its buoyancy and lifts the device out of the sediment and back to the water surface. The system is relatively portable and lightweight compared with other deep-water coring systems. The Mackereth can be deployed in water depths to ~100m.