A marine exhaust hose must be carefully designed to carry toxic and/or noxious gases outside. Indoor enclosed spaces can quickly fill up with poisonous exhaust gases such as hydrocarbons, carbon monoxide and nitrogen oxides, if they are not properly vented to the outdoors.
Also, it must be taken into account that the gases coming from the engine are very hot; therefore the hose must be heat-resistant, and it must not pass through or near anything that can burn or can be damaged by heat.
In the picture you can see how corrosion is producing an exhaust leak.
Check your exhaust mixing elbows. If its leaking water, it’s leaking exhaust gasses as well – Carbon Monoxide!!!
Hose is cracked and leaking as well.
