An oil supplying apparatus for supplying the oil to an engine of a watercraft can be provided with an oil sump, a vapor-liquid separation chamber, a scavenging pump for sending the oil in the oil sump to the vapor-liquid separation chamber, a transfer path for returning the oil from which air and blow-by gas have been separated in the vapor-liquid separation chamber to the oil sump, a feed pump for supplying the oil in the oil sump to the engine, and openings and for returning oil used to lubricate the engine to the oil sump. The oil sump can be provided below the crankcase, and the vapor-liquid separation chamber can be provided to a side surface of the engine.