Patent ID: 6939185

Claim:
An exhaust system for a small watercraft, comprising: an exhaust chamber having a predetermined volume, within which an exhaust gas discharged from an engine flows, the exhaust gas containing water supplied at a position of the exhaust system; and an exhaust pipe configured to allow an inside of the exhaust chamber and an outside of the watercraft to communicate with each other, and having an upstream end portion in a flow passage of the exhaust gas, which is connected to the exhaust chamber and a downstream end portion in the flow passage of the exhaust gas, which is connected to a body of the watercraft so as to open outside the watercraft, the exhaust pipe being configured to discharge the exhaust gas from the exhaust chamber outside the watercraft, wherein the upstream end portion of the exhaust pipe is configured to protrude into the exhaust chamber to a vicinity of a lower end of the exhaust chamber and has an upstream opening end face that opens substantially downward in the exhaust chamber so as to be spaced apart a predetermined distance from an inner surface of the exhaust chamber which is opposed to the upstream opening end face, and wherein the predetermined distance between the inner surface of the exhaust chamber and the upstream opening end face satisfies a formula represented by: D /3 ≦L≦D where L is a distance between the upstream end face of the exhaust pipe and the inner surface of the exhaust chamber which is opposed to the upstream opening end face, and D is an inner diameter of the upstream end portion of the exhaust pipe.