Abstract: A vessel (1) with a transfer installation for cargo and persons towards an offshore construction (12) comprises means for stabilizing its position at sea relative to the offshore construction (12), a telescopically extendable beam assembly (2) that comprises telescopable beam elements (2a, 2b), which beam assembly (2) with its one outer end (15) is rotatably connected to the vessel (1) by means of an axle system (7a, 8a, 9a), and a driving device designed to bring the other outer end (16) of the telescopically extendable beam assembly (2) in contact with a landing provision (13) of the offshore construction (12). The telescopically extendable beam assembly (2) is provided with means for moving a transportation carriage (14) back and forth between both outer ends (15, 16) along the telescopically extendable beam assembly (2), wherein the transportation carriage (14) is provided with a support (20) for carrying the cargo and persons.