The telescopic device is used for hanging realted boat on board.The device arm could be moveable horizontally,also,which could hang the boat from the parking lacation to water position,also recovery it from the water position to the parking location,and the lifting device could make vertical movement of the boat.Vertical movement and horizontal movement can be in independently controlled manner.This device meets the 1974 International Convention for the safety of life at sea,International life-saving appliance regulations(LSA)&IMO,MSC.81(70) and other regulatory requirements.