Similan islands are a group of 9 small islands located some 70km off the shore. You usually get there by booking a trip with one of the tour companies which is also what I did. Fantastic Similan (all inclusive tour 2100 baht) came to pick me up from the hotel at 7:30 am to take me to their docks at the Tap Lamu Pier for a 9am departure to the islands.
The trip to the first island took little over an hour with a speed boat. When you arrive at the first island you understand why people visit the islands: the waters around the islands are incredibly clear and the sand is like white powder. We also had our lunch at the first island.
After lunch we continued to the second island where we got a better opportunity to snorkel. There were plenty of even large fish in the water but the corals were a let down: in some places they were dead, in others their colors had faded to brown.
After snorkelling, we continued to yet another island with an amazing beach and an opportunity to walk up to the little cliff next to the beach with some great views.