That's what I thought as well, I just wasn't sure if it balanced out against a cavitation based propulsion system - maybe it does(!), but idk lol. I just assumed it would be relatively easy to detect via sonar but with a very different profile obv.

Edit*: then again, we are comparing the volume of cavitation vs a conventional submarine drive system. Could very well be that the conventional engine with more moving components is just straight up louder than bubble explosions >.>