To provide a rotary crane type boat lifting apparatus which is adapted to secure a sufficient work space on a deck and simplify the structure of the boat lifting apparatus.

The boat lifting apparatus comprises a crane boom 6 which is rotated about a vertical axis and is swung out from a deck 2, a swing device 8 which drives the crane boom 6, one wire rope 7 which is fed out of the front end of the crane boom 6 via a sheave 12, one winch 9 which winds the wire rope 7, and a rotary pivot 21 which supports the base end of the crane boom 6 rotatably. The rotary pivot 21 is arranged to extend down from a ceiling 31 extending over the deck 2, and the crane boom 6 is rotated to carry the onboard boat 4 hung by the wire rope 7 in and out of a mother ship 1.