Well, in conclusion, I was unable to find a single college that would grant my son credit for his PADI Open Water, Advanced Open Water, or Rescue Diver courses, and therefore, he gets no PE credit. :-(
I reached out to PADI and ACE multiple times, but they could not provide me with the name of ONE SINGLE SCHOOL that would grant credit, so I was pretty disappointed.
There was one school in Santa Barbara that said that if my son enrolled there and took 12 units of courses, they might be able to grant him a couple of units of credit, but they couldn't even guarantee it.
Honestly, I'm shocked this "college credit for scuba classes" is so widely advertised and talked about because it doesn't look like it exists.