A pressure method of cleaning loose material out of an open-ended cased pile, caisson or cofferdam cell. Usually compressed air is introduced into the water at the bottom of the casing via a small pipe inside a larger pipe. Air is directed upward out of the larger pipe; this upward flow tends to lift material in the pile.
A small hand-held dredge that works like a vacuum cleaner, used to clear away the sand on the seabed.
an item of diving equipment, based on apipe, used in nautical archaeology to suck small objects,sand and mud from the sea bed and totransport the resulting debris upwards and away from its source