I am looking at blueprints. I see air induction, but am unsure where it leads, from the plans I see.
If a pressure-hull exhaust outlet valve open while diving, there more than likely would be at least one engine valve open in the engine open at any given time, to let water in the cylinder.
What's worse: at depth, because the ocean pressure is on the outside of the valve, water entering the exhaust might have enough pressure to open engine valves.
https://bluerobotics.com/learn/press...th-calculator/
That stated, salt water entering an engine is bad.