To move a ship by driving a spud on the starboard and port respectively at the hull center and a spud at the stem, three spuds in all.

A port spud 1 and a starboard spud 2 at the hull center of a ship A and a stern spud 3, three spuds in all, are driven. One of the port and starboard spuds 1, 2 and the stem spud 3 are extracted, a bucket 5 is lowered on the sea bottom centering on the other spud 1, a crane 4 is rotated with the bucket 5 used as an anchor, and the ship A is turned. Then one of the port and starboard spuds 1, 2, e.g. the starboard spud 2, is driven, the port spud 1 is extracted, and the ship A is likewise turned in the opposite direction by the force of the crane 4 and the bucket 5 centering on the starboard spud 2. When the ship A is returned to the original direction, the other two spuds 1, 3 are driven, and the ship A is kept stationary. The ship A can be advanced in sequence, and the rotative movement of the ship A by the crane 4 and the bucket 5 can be conducted via small force with little resistance of tidal currents and wind.