Activities on the Island Trekking Adventure through Koh Rong Sanloem’s network of pathways and uncover the island’s hidden beauties. Plankton Tour A must do while staying on the island : swim at night with billions of bioluminescent planktons, a trully unique experience. Diving Enjoy Koh Rong Sanloem’s sea life to its fullest ! There are many diving options on the island for both seasoned and amateur divers. Private Boat Tours Rent a longtail or speed boat for a day and explore ! The driver can take you fishing, snorkeling, to delicious restaurants, to visit other islands and more.