My dad was part of a special Navy program after the war to convert an American sub with a snorkel so they could run the diesels under water, captured German tech. Called the GUPPY program. They had a lot of problems with it, and had some high level civilian support, he said Charles Kettering came out to the boat for consultations. Kettering worked for Delco, or really, he WAS Delco, having invented the ignition distributor and the electric starter some years prioe and was a pretty sharp guy.
Dad said one of the problems was the diesels - huge Fairbanks-Morse engines would draw lots of air when running at full tilt. A ball check valve on the snorkel kept sea water from being ingested into the intake when seas were rough, and this resulted instant very wide swings in air pressure. Said he’d wake up in his bunk with blood coming out of his ears. Nuclear propulsion made all of those experiments moot, anyhow.
The Germans had the same problem with their snorkel apparatus.