Abstract: An exhaust gas silencing assembly or unit of the wet-type receives the exhaust gases from a water cooled internal combustion engine used to power a water-going vehicle, such as a speed boat, and the coolant water from the water jacket of the engine. The exhaust gas and water mixture may be expelled through a downwardly directed combined exhaust gas and water outlet of the silencing unit, or in response to opening a valve in an exhaust flow tube of the unit, exhaust gases and some of the water may be expelled directly out an outlet opening of the silencing unit. When the water and exhaust gases are expelled downwardly into the turbulent waters and foam of the wake of the boat the level of sound emanating from the silencing unit is substantially minimized. Upon opening of the valve at an outlet end of the silencing unit to provide straight through fluid flow the sound level of the engine is at a maximum, but the back pressure imposed on an engine is at a minimum for providing maximum engine performance.

Abstract: A pressure operated speed indicating system for a vehicle operating in a fluid, such as a speed boat, has a mounting bracket which enables a pressure sensing or pitot tube having a pressure sensing opening to be placed in an optimum position with respect to the boat. The mounting bracket grips the strongest portion of the tube to minimize tube deformation or breakage in use. The mounting bracket also assures that the pressure sensing opening of the pitot tube will remain in a forward facing position substantially transverse to the longitudinal axis of the boat. An improved connection fitting for connecting the pitot tube to a resilient conduit placing the tube in fluid pressure transmitting communication with a pressure operated speedometer is also provided. This fitting facilitates installation or replacement of a pitot tube in the system.