cavitation: is when, basically, bubbles are produced from any propeller/pump/etc.
I’m guessing they are purposely producing “bubbles” to lower the coefficient of friction against the water....but I’m not sure how that is good on the “stealthiness” of the craft.
I could see it now, the sailors are all fed beans 24/7 allowing them to produce cavitating gasses. Green technology at its finest. They could call the first ship the USS Al Gore. I am being series here. This is hugh, it would be a perfect name, jet driven craft that is full of hot gas.