An apple corer is a device for removing the core and pips from an apple. The core can then be removed from the apple corer. A simpler version known as a "pineapple corer" removes only the core of the pineapple. Seabed surface sampling can be done with a grab sampler and with a box corer. Samples of deeper layers can be obtained with a corer mounted in a drill. There is also on board, the CASQ square gravity corer (25x25cm x12m long). The corer is lowered vertically until it impacts with the seabed. It originates from the Reineck box corer and the USNEL box corer. A more advanced version of the sounding weight is the gravity corer.