Animating a beach background?

I am making a background for a 2D game.  I'm trying to figure out how I should create an animated beach background.

Ideally what I want is something like the beach backgrounds I see in a lot of anime shows.  I am looking at these because 1) they are actually treated as backgrounds without a strong focus on them; eg they are not making detailed waves crashing that demand a primary focus, 2) they seem to be made relatively simply without too much cost, 3) they still maintain a relatively realistic design and don't look too cartoonish/abstract, and 4) Weeb.

But I am having the hardest time figuring out how they are pulling off that effect.  I've been looking for clips and gifs to study but most of what people try to share are focused on other elements of the episode and don't give me a clear view of the ocean.
What I can tell is that there is a layer of sparkles, and there is some kind of subtle motion of waves so that the water doesn't look static.  But how are they actually doing this?

There seems to be some kind of pattern to the sparkles to suggest motion; they don't just have random points blink in and out which would look more like a crystal than an ocean.  And I can't get a clear image of the wate to tell anything of what they are doing to make it look like it is moving.

Any help in understanding what they are doing would be appreciated; or a link to a clear tutorial for another method I might try would be nice.