An indicator assembly for watercraft having an engine is provided. The indicator assembly comprises a first detector for detecting an operating condition of the watercraft, such as a fluid level, an indicator for indicating this detected operating condition, a switching assembly for actuating the indicator, a second detector for outputting a signal to the switching assembly when the engine is in the on or running state. The indicator assembly is designed so that the switching assembly actuates the indicator when the switching assembly receives the signal from the second detector but does not actuate the indicator when the signal is not received by the switching assembly after a predetermined time.