Any recommendations on a good submarine simulator on Steam (see details)

I am a sucker for submarine movies. My favorite WW2 movie is called The Enemy Below and I’m in the middle of a WW2 submarine book series called Crash Dive.

I have Steam on my PC and I’m wondering if there is a good submarine simulator for WW2 Pacific theater combat? IT doesn’t need to be cheap. I’m looking for fun and good.