Any water coming in through the engine exhaust valves kills the engine and can sink the boat. My exhaust outlet is high enough to be out of the water regardless of angle of heel. I think this is great insurance
on a voyaging boat. If you are starting from scratch on your exhaust set-up, now is the time to move the outlet to a high and dry location. On a steel
boat it is easy to move holes around. Remember you may not just be heeling when sailing in good conditions... you may be heeling because the mast
is broken, sails
are in the water, winds are 70 knots, and you cannot cut it all loose for hours. You also need to be able to sail (and therefore heel) and start and stop the engine at will. Often you need both sails
and the engine to cross bars, get off lee shores, etc.