ARRANGEMENT AND METHOD IN A SHIP

The ship comprises a hull (200), at least one propulsion unit (100) comprising a propulsion engine (30), transmission means (40), at least one propeller (50) connected via the transmission means (40) to the propulsion engine (30), and a oscillation sensor (300) situated in the vicinity of the at least one propeller (50) in order to sense cavitation of the at least one propeller (50). The arrangement comprises further a control unit (400) for controlling the propulsion engine (30), said oscillation sensor (300) being connected to the control unit (400), whereby the output signal of the oscillation sensor (300) is analyzed in the control unit (400) in order to detect whether a worse degree cavitation is emerging, and indicate that a worse degree cavitation is emerging on a display unit at the navigation bridge and/or regulate the rotation speed and/or the power of the propulsion engine (30) when worse degree cavitation is emerging.