To move a hull smoothly and stably by providing a spud at the stern and starboard and port spuds at the hull center, providing a thrustor at the stern, turning the hull with the thrustor in the board direction centering on one of the starboard and port spuds, likewise turning the hull centering on the spud on the other board, and fixing a ship after the hull is returned to the original direction.

Three spuds 2, 3, 4 are driven, and a thrustor 5 is stopped. The starboard spud 3 and the stern spud 2 are lifted, the thrustor 5 is operated in the port direction, and a hull 1 is turned to the left centering on the driven port spud 4. When the hull 1 reaches the prescribed angle, thrustor 5 is stopped, and the starboard spud 3 is driven to stop the hull 1. The thrustor 5 is operated to the starboard side in the opposite direction, and the hull 1 is turned centering on the starboard spud 3. When the hull 1 is returned to the original angle, the thrustor 5 is stopped, and the port spud 4 and the stern spud 2 are driven to complete movement. The hull 1 can be moved surely, smoothly and stably.