Trip base · Thailand
Similan Islands
Four sites in the Andaman Sea, mostly dived by liveaboard from Khao Lak. Koh Bon has manta cleaning stations and Richelieu Rock is known for whale sharks. The national park closes every year from 16 May to 14 October.
Strong fit for March
28°C+
- Strength: Water 28–29°C in March
- Strength: 4 of 4 sites are in season in March
- Strength: Calm seas on almost every day
Pack a shorty or 3 mm wetsuit for March.
Why this match: 40 + 26 + 20 + 11 = 97
- Season40 / 40
- 4 of 4 sites are in season in March; calm on almost every day.
- Water26 / 27
- Average 29°C; your minimum is 28°C. Pack a shorty or 3 mm wetsuit.
- Your level20 / 20
- No level picked, so all 4 sites count.
- Weather11 / 13
- Rain on about 1 day in 3; no real storm risk.
Month by month
Season: best December to April.
| Month | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Season | January: Best | February: Best | March: Best | April: Best | May: Off season | June: Off season | July: Off season | August: Off season | September: Off season | October: Off season | November: Good | December: Best |
| Mantas | January: Likely | February: Likely | March: Likely | April: Likely | May: Possible | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Possible | November: Likely | December: Likely |
| Whale sharks | January: Possible | February: Likely | March: Likely | April: Likely | May: Possible | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Possible | November: Possible | December: Possible |
| Hammerheads | January: We don't know yet | February: We don't know yet | March: We don't know yet | April: We don't know yet | May: We don't know yet | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: We don't know yet | November: Possible | December: We don't know yet |
| Reef sharks | January: Likely | February: Likely | March: Likely | April: Likely | May: Likely | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Likely | November: Likely | December: Likely |
| Turtles | January: Likely | February: Likely | March: Likely | April: Likely | May: Likely | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Likely | November: Likely | December: Likely |
| Dolphins | January: We don't know yet | February: We don't know yet | March: Possible | April: Possible | May: We don't know yet | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: We don't know yet | November: We don't know yet | December: We don't know yet |
| Water | 28° | 29° | 29° | 30° | 30° | 29° | 29° | 29° | 29° | 29° | 29° | 29° |
| Rain days | 6 | 3 | 10 | 17 | 27 | 27 | 28 | 28 | 28 | 27 | 18 | 9 |
| Calm days | 31 | 28 | 31 | 30 | 28 | 24 | 22 | 22 | 26 | 29 | 29 | 30 |
| Storm risk | – | – | – | – | – | – | – | – | – | – | 7% | – |
Storm risk: – means under 5%.
Dive sites here
4 sites on Divetip.
- Richelieu RockReef · Intermediate · max 35 m
- Similan IslandsReef · Beginner · max 30 m
- Koh BonReef · Intermediate · max 30 m
- Koh TachaiReef · Intermediate · max 35 m
Getting there
Fly to Phuket (HKT). Road to Thap Lamu pier, where most liveaboards leave: about 1 h.
Liveaboard or day boat.
What diving costs
A day of diving from about €136
A day of diving
Sea Bees Diving (MC Stingray, Khao Lak): THB 5,600 for 2 dives (about €149)
Similan Islands day trip (Thu-Sun, Islands 5-9); Koh Bon/Koh Tachai days 5,800 THB, Richelieu Rock 6,000 THB. Includes tanks, weights, lunch, coffee/tea/water/fruit, divemastering, free pick-up from Khao Lak/Bang Niang/Pakarang. Excludes Similan National Park fee (diver 700 THB, non-diver 500 THB); equipment rental listed separately (full set 750 THB). Schedule valid 01.11-30.04 (year not stated).
Sunrise Divers (Sundancer catamaran, from Khao Lak): THB 5,100 for 2 dives (about €136)
2-dive Similan day trip (Islands 5-9 or Koh Bon); Tuesday 3-dive trip (Koh Tachai, Koh Bon, Premchai Wreck) 6,500 THB. Includes breakfast, lunch, soft drinks, transfers from Khao Lak. Excludes equipment (900 THB), National Park fee (700 THB diver / 500 THB non-diver, cash on board), Phuket transfer (2,400 THB per car one way). Season November-April (year not stated).
Wetzone Divers (Khao Lak): THB 6,800 for 2 dives (about €182)
'Day trip (2 dives) all inclusive from 6.800 THB'. Lunch included; page does not itemise whether park fee, equipment or transfers are in the price.
Liveaboards
Oceanic Dive Center (Manta Queen 1/3/6/7): THB 21,500 for 4 nights (about €574)
4 days/4 nights, 15 dives, 4-berth cabin (twin/double 23,500). Includes equipment rental. National Park fees extra (4 days 1,800 THB). Undated; page shows other conflicting figures (e.g. 'Prices start at 25,500').
Wetzone Divers (MV Manta Queen 2): THB 20,000 for 3 nights (about €534)
4 days/3 nights, 10 dives, 4-bed non-ensuite (twin/double 22,000). National park fees 2,300 THB and equipment (600 THB/day) extra. Departures Oct 2026-May 2027.
Wetzone Divers (MV Bavaria): THB 35,900 for 3 nights (about €958)
4 days/3 nights, 13 dives to Koh Bon, Koh Tachai, Richelieu Rock and Surin, Standard Twin (Similan-only 4D/3N 10 dives from 26,500). Fuel surcharge and park fees extra 'depending on the safari length'; equipment 600 THB/day.
Prices checked 8 November 2026; park fees and equipment often extra.
Non-divers: snorkeling by boat only
Snorkeling is by boat only: speedboat snorkel day trips from Khao Lak visit the islands' beaches and reefs between mid-October and mid-May, and non-divers can also ride along on dive day boats for a reduced fare.
Book your Similan Islands trip
- Find Similan Islands trips on Klook (partner link, opens in a new tab)
- Search flights on Aviasales (partner link, opens in a new tab)
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