Abstract: A marine engine exhaust assembly (7) is provided with water flow path control devices which minimize back pressure. Lower intermediate elbow portions (8) and the respective bullhorn upper legs (12) are formed and joined in a manner to provide a continuous common gas-water passage which is axially linear in a fore-to-aft direction. The common gas-water passages are formed to provide a gradual reduction in cross-sectional area from top to bottom. The wall contours of the intermediate elbows gradually merge from circular at the upper end to generally elliptical at the lower end. In addition, the wall contours of the upper bullhorn legs are generally elliptical (FIG. 5) at their upper ends for communicating with the intermediate elbows, and gradually merge into a rectangular shape (FIG. 6) in the area of the bullhorn bends (13), which continues on to adjacent the bullhorn discharge portion.