The actual excavation, is undertaken with the use of an airlift. By means of a compressor, air is pumped down through a small hose to the bottom where it enters a larger hose and then rises to the surface. As the air strives for the surface a suction-effect is created making it possible to excavate artefacts and ships' structure. At the surface the hose is connected to a sieve where small unseen objects can be taken care of. It is extremely important that the diver does not place the mouthpiece of the airlift in direct contact with the find material or sediments. If this occurred there would be significant risk of destroying information or sucking up artefacts. By lying as still as possible on the bottom when working, the diver minimises the risk of destroying archaeological information or reducing visibility in the water. Before removing an object from its position on the bottom, its location and context in the sediment must be fully determined by measuring and further excavation in order to prevent unnecessary loss of information.