at an appropriate distance from the sea bed via a pair of cables 12 13 one cable extending from each side of a lifting means 14 on the mother vessel 10 and there is provided a further cable 16 from adjacent the bow of the vessel 10 as illustrated in fig2 the wing dredger has a hydrofoil cross section and is rectangular in plan it is constructed as a casing comprising vertical end walls 17 connected by laterally extending wall 18 which provide lower angled faces 19 to provide a downward component of force when acted on by tidal flow providing as stability the upper wall 21 is generally flat referring to fig3 it will seen that the wing dredger 11 is constructed of three units a front unit 11a and mid unit 11b and a rear unit 11c connected together so that the wing dredger can be split into three sections for ease of transportation each of the three units 11a 11b and 11c are of steel skin construction and units 11a and 11c are hollow closed boxes the hollow closed boxes are divided into compartments by suitable bulkheads it will be seen from fig3 that the wing dredger is symmetrical about its lateral axis so that it can be used in either direction with the respective end wall 18 leading the dredger 11 is provided with two closed vertical bores 22 which.