Are these smooth patches langmuir circulation?

Hi Reddit, hoping you can help explain a sea phenomenon I see every so often when the wind and seas are calm. It appears hopefully as shown in the photos where there's what looks like a long patch of water that's a different colour and texture to the surrounding water, looks a bit like an oil slick. Almost always appears in the exact same spot when visible.

I've googled and seen that langmuir circulation could be an explanation although don't really understand the concept. My thoughts were that there's something underwater changing how the water moves (unlikely as quite easy to see rocks in the water here) or currents that happen to be in the right direction. I've never really seen it as clear or regular as where I am now.

Photos show the area a few hours apart and then the next day with similar conditions but now gone.

Can any clever Redditors help?