Three Trees, named after the three trees directly above the dive site on Similan Island 9, is a big wide white sand channel with some awesome corals and fish encounters
Giant sponge coral, Three Trees, December 2022 © chris@divehappy.com
Two of these bommies are covered in soft corals and often glass fish. The bommies are big – a good 10 metres by 5 metres, so there’s plenty of room for a group of divers to circle around.
Barracuda in the deep, Three Trees, May 2024 © chris@divehappy.com
These are the warm up to the main attraction which is the giant barrel sponge at least two metres high which sits on a rock outcrop resplendent in the middle of the channel, surrounded by soft corals. It is an absolute whopper.
Soft corals, Three Trees, December 2022 © chris@divehappy.com
While the barrel sponge usually gets all the attention, there are some beautiful patches of soft corals hanging on to the rocks around the sponge which are worth a look too.
Orange fan, Three Trees, Similan Islands, December 2022 © chris@divehappy.com
There are also some lovely fan corals here too, which is all the more surprising given how fierce the current can get – they’re super resilient.
Soft corals on white sand, Three Trees, December 2022 © chris@divehappy.com
Further along and down deeper around 28 metres is another clump of rocks which seems to be a magnet for marine life – one time we were there a huge school of barracuda sailed in over the rocks, while on another occasion we were caught in the middle of a fusilier blizzard, with thousands of them rushing past us.
Running fusiliers, Three Trees, February 2024 © chris@divehappy.com
Be aware that to get from the entry point to the bommies and then onto the barrel sponge rock requires covering a fair bit of ground, so pace yourself. It’s hard for the boats to drop divers directly on the bommies because the current means you could easily miss them and then be drifting in the blue.
The chonky barrel sponge, Three Trees, February 2024 © chris@divehappy.com
Picking an entry time so it’s near slack tide is important as it can be ripping otherwise. A gentle drift between the bommies and then onto the side of the channel to explore the
shallows is ideal rather than getting swept off and surfacing out in the channel.
Yellow Snappers, Three Trees, May 2024 © chris@divehappy.com
All photos taken during Similan diving seasons 2022-2023 and 2023-2024. I’ll probably add more during the 2024-2025 season too. The Similan dive season runs from October to May each year. The Similan Marine National Park is closed from mid May to mid October each year, so don’t plan a liveaboard trip then!
Recommended Similan Liveaboards October 2024 to May 2025
Blue Dolphin Liveaboard

The Phinisi Liveaboard

Smiling Seahorse Liveaboard

The Junk Liveaboard

2025 Thailand Last Minute Liveaboard Deals
- Thailand Aggressor - 17 May 2025 - from €2,271.00 - South Andaman Sea (Chalong - Chalong) - Travel the World Special! (25% OFF)
- Thailand Aggressor - 30 Aug 2025 - from €2,260.00 - South Andaman Sea (Chalong - Chalong) - Travel the World Special! (25% OFF)
Similan Islands Dive Sites List
- West Of Eden
- Shark's Fin Reef
- Christmas Point
- Three Trees
- Tuna Wreck and Hideaway Bay
- Koh Bon
- Ao Suthep
- Richelieu Rock
Similan Liveaboards Overview
- Luxury Similan Island Liveaboards
- Mid Range Similan Island Liveaboards
- Budget Similan Island Liveaboards
- Last Minute Liveaboard Deals
- Diving The Similan Islands 2024: A Quick Guide
- Similan Islands Dive Sites
- Diving Thailand Guide
Upcoming Similan Liveaboard Availability and Pricing
Check availability and pricing for all Similan Islands liveaboards departing in
- March 2025 | April 2025 | May 2025 | October 2025 | November 2025 | December 2025 | January 2026 | February 2026
(The Similan National Park is closed from mid May to mid October each year)
Similan Liveaboards Trip Reports
Photos from each of the Similan liveaboard trips I've been on over the years.
- Similan Islands Liveaboard Trip Report 21-25 November 2024
- Similan Islands Liveaboard Trip Report May 2024
- Similan Islands Liveaboard Trip Report 21 - 25 February 2024
- Similan Islands Liveaboard Trip Report 15 - 19 February 2024
- Similan Islands Liveaboard Trip Report December 2023
- Similan Islands Liveaboard Trip Report October 2023
- Similan Islands Liveaboard Trip Report April 2023
- Similan Islands Liveaboard Trip Report February 2023
- Similan Islands Liveaboard Trip Report December 2022
- Similan Islands Liveaboard Trip Report February 2020
- Similan Islands and Myanmar Trip Report March 2015