Abstract: A device (1) for converting a monohull vessel (2) into a multihull vessel, includes a support structure (3) which is removably fixed to the vessel (2) and at least one lateral float (4) which is solidly articulated with the support structure (3) around at least one geometrical axis (BB?). The aforementioned float (4) can occupy (i) a first stable deployed position in which it is parallel to the vertical longitudinal geometric plane (PP?) containing the keel line of the vessel (2) and, at the lowest point of the keel line thereof, it is disposed beneath the geometric axis (BB?) and (ii) a second stable collapsed position which is separated at an angle from the first position. A vessel equipped with the device is also disclosed.

Abstract: The invention relates to a device (1) which is used to convert a monohull vessel (2) into a multihull vessel, comprising a support structure (3) which is removably fixed to the vessel (2) and at least one lateral float (4) which is solidly articulated with said support structure (3) around at least one geometrical axis (BB?). The aforementioned float (4) can occupy (i) a first stable deployed position in which it is parallel to the vertical longitudinal geometric plane (PP?) containing the keel line of the vessel (2) and, at the lowest point of the keel line thereof, it is disposed beneath the geometric axis (BB?) and (ii) a second stable collapsed position which is separated at an angle from the first position. The invention also relates to a vessel which is equipped with said device.