The present invention relates to an exhaust system for a combustion engine of a marine vessel. The exhaust system includes an exhaust system inlet configured to be coupled to an exhaust gas outlet of the marine engine, one or more exhaust system outlets, and an exhaust gas flow path extending from the inlet to the one or more exhaust system outlets and having a forward flow direction from the exhaust system inlet and a reverse flow direction extending from at least one of the one or more exhaust system outlets. The exhaust system further includes a flow redirection arrangement in the exhaust gas flow path for restricting a flow of liquid flowing in the reverse flow direction, the flow redirection arrangement comprising at least one flow redirection feature configured to redirect a first stream of the liquid toward the forward flow direction to collide with a second stream of the flow of liquid. The invention also relates to motor assemblies and marine vessels having such exhaust systems.