What are swimming requirements in high school?

If a high school has swimming as a requirement for graduation, what are the exact swim skills students need to demonstrate? Is it some basic strokes and ability to swim the length of the pool and back? Is diving a requirement?

I know that is will vary from school to school, I’m only trying to get a general idea of how much swimming/diving students are expected to master before graduation.

If you are responding with the swim requirements of a particular high school or school district, it would be great if you can mention which state the school is located in.