To provide a device able to perform lowering/receiving work of a small-sized boat and holding in a cradle tip end, by a stable manner, in the boat lift device provided with a moving type cradle (suspension pillar) to suspend the small-sized boat by a wire rope delivered from an upper end of this cradle.

An involute horn 23 is extension provided in respective upper end lower side of a pair of cradles 5, and when the cradle 5 is provided in a tip end side (center side of a hull) of a davit frame at receiving time of the like of a small-sized boat, a disk member 32 fixed to a wire rope 12 suspended from the cradle 5 is received to a notched part 23A of the involute horn 23, so as to prevent delivery of the wire rope 12 from the cradle 5. On the other hand, when the cradle 5 comes to a base end side (side of the hull) of the davit frame, the disk member 32 is made to escape from an opening part 23B, so as to deliver the wire rope 12 from an upper end of the cradle 5.