Koh Samui green murky water

Hey everyone,
Currently in Koh Samui and I was wondering if anyone can help. All the beaches have greenish, murky water.

When you enter it seems nice but then if you are fully immersed, you can't even see your legs.

Wanted to do some snorkeling and freediving while I'm here but it's impossible in this water.

Anyone knows why this is happening and when it might end? Is it just Koh Samui or is it Phangan and Tao too? We want to go scuba diving too but not in water like this :D

Any info is really welcome cause we came here for crystal clear water and this is not what we were expecting.