Pigeon Island, located off the northeastern coast of Sri Lanka, is a stunning little gem known for its beautiful beaches and vibrant marine life. This small island is part of a national park and is famous for its crystal-clear waters, making it a popular spot for snorkeling and diving.

It's quite expensive to go as you have to pay the national park fee to enter, but its an incredible place for seeing sea turtles and reef sharks.
We used Divinguru for our tour here and they were great. I was in a group of 6 people with a guide, who was half there to ensure I didn't go into the protected areas and half there to find turtles and fish and sharks