A marine sanitising and deodorising device comprises a reservoir (14) for containing sanitising fluid, a dose controllable pump (16) for discharging a predetermined dose of sanitising fluid from the reservoir (14) into a water inlet conduit (2) of a marine toilet system, a flow detector (8, 9, 10) for detecting the flow of water within the water inlet conduit (2), and a controller (17) for controlling the dose controllable pump (16) upon flow detection by the in use flow detector (8, 9, 10). A toilet system having the said device, a marine craft having the toilet system, and a method are also provided.
