Photo: Corentin Largeron / Unsplash
Phi Phi & Koh Lanta
Phi Phi and Koh Lanta anchor the central Andaman Sea, a cluster of accessible day-trip reef diving reached from Phi Phi, Koh Lanta, Krabi or Phuket. This is the region's all-rounder and training area, not a big-pelagic hotspot. The honest draw is scenic, mostly easy limestone-and-coral reef diving with a reliable cast: Indo-Pacific leopard (zebra) sharks resting on the sand, blacktip reef sharks patrolling the shallows, hawksbill turtles, and a solid macro line-up of seahorses, ghost pipefish and nudibranchs. The core sites are Koh Bida Nok and Bida Nai off Phi Phi, plus the open-sea trio of Shark Point (Hin Musang), Anemone Reef and the King Cruiser wreck between Phuket and Phi Phi, and Koh Haa's caverns and lagoon near Lanta. Most dives run mild to moderate current and suit Open Water through Advanced divers. Water is warm year-round, roughly 28-30C, so a 3mm is plenty. The best conditions are the dry season, roughly November to April, when seas are calm and visibility is best; the southwest monsoon (May to October) brings rougher water and more variable viz. Note the seasonal split on access: the King Cruiser, Shark Point and Anemone Reef sit outside the park boundaries and dive year-round, while the Koh Haa sites inside Mu Ko Lanta National Park close mid-May to mid-October.
What makes it special
- Reliable resting Indo-Pacific leopard (zebra) sharks and shallow blacktip reef sharks at Koh Bida Nok/Nai and Shark Point
- The King Cruiser, an 85m car-and-passenger ferry that sank in 1997, upright in ~18-30m near Anemone Reef
- Koh Haa's 'Cathedral' interconnected caverns and a sheltered lagoon good for training and easy dives
- Strong macro: seahorses, ornate ghost pipefish, nudibranchs and frogfish across the reefs
Price range
$
Trip length
3–7 days
Diver level
Open water
Trip type
Day trip, Land based
Price is per person for a typical trip, excluding international flights ($ = under $2,000).
Cheap-to-mid. Two-to-three-dive day trips from Phi Phi, Koh Lanta, Krabi or Phuket commonly run roughly 2,500-4,000 THB (about $70-115) including gear and lunch; a fun-dive from a shore base is often ~1,200-1,800 THB per dive. A week of land-based day diving plus a budget-to-midrange room lands well under $2,000 per person. National park fees are extra and paid in cash where sites fall inside a park.
Best time to dive
- Current
- Mild
- Water temp
- 28–30.5°C (coldest Jan, warmest Apr)
- Visibility
- 10–25m — Commonly 15-25m in the dry season (November-April) with calm seas; drops to roughly 10-20m in the monsoon and after heavy rain. Bida sites are often quoted at 20m+ in good conditions.
- Getting there
- Easy — Day trips from a coastal base, about 2h from the airport, then a short boat.
- Experience
- A genuine mix. The Bida islands, Koh Haa lagoon and reef shallows suit Open Water divers and courses. Shark Point, Anemone Reef and especially the King Cruiser wreck (sitting ~18-30m with shifting current) are better for Advanced Open Water divers with some experience; the wreck is no longer safe to penetrate.
Nearest airports
- HKT — Phuket International Airport (Main international airport; day boats to Shark Point/King Cruiser and Phi Phi leave from Phuket piers, or ferry ~2h to Phi Phi/Koh Lanta)
- KBV — Krabi International Airport (Closer to Koh Lanta and Phi Phi; ~1.5-2h by road-and-ferry transfer to Lanta, or day boats from Krabi/Ao Nang)
Permit required
Sites inside Hat Noppharat Thara-Mu Ko Phi Phi National Park (the Bida islands) and Mu Ko Lanta National Park (Koh Haa) require park fees, collected in cash by operators. The open-sea sites (Shark Point, Anemone Reef, King Cruiser) lie outside park boundaries and carry no park fee.
Foreign-adult national park entry is typically 400-500 THB per park per day for the Phi Phi and Lanta parks, paid separately in cash at check-in. No fee applies to the outside-park sites. Confirm current amounts at booking.
Marine life
Sightings are never guaranteed — the bars show typical likelihood by month.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Hawksbill turtles are commonly seen grazing the coral at the Bida islands and Koh Haa and are among the region's most dependable larger animals.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Bluespotted ribbontail rays are common on sandy patches and under coral ledges across the region's reefs.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Barracuda hang around the King Cruiser wreck and Anemone Reef pinnacles, sometimes in loose schools.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
The Indo-Pacific leopard (zebra) shark is the region's signature reliable sighting, resting on sandy patches at the Bida islands, Shark Point and Hin Bida through the year. Numbers are best in the calm dry season when boats reach the sites most consistently.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Spotted eagle rays pass over the reefs and pinnacles occasionally, more often at Koh Haa and the outer sites; never guaranteed.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Juvenile blacktip reef sharks patrol the shallow bay at Koh Bida Nok and are among the most reliable shark encounters in the central Andaman, often seen on a single shallow dive or even while snorkeling.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Trevally hunt around the outer pinnacles and the wreck, most often on dives with some current.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Green turtles turn up on the reefs alongside the more frequent hawksbills, though in smaller numbers.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
A wide range of nudibranchs is present year-round across the reefs, a staple of the region's macro diving.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Ornate ghost pipefish are a prized macro find at Koh Haa and the Bida reefs, seasonal and easier to spot with a guide who knows the current haunts.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Tigertail seahorses cling to soft corals and rubble at Koh Haa and the sheltered reefs; a macro highlight but easy to miss without a guide.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Whitetip reef sharks are seen from time to time at the deeper reefs and pinnacles, less reliably than the leopard and blacktip sharks.
Dive sites
Worth knowing before you book
- This is accessible reef and macro diving, not a big-animal destination — no manta or whale-shark reliability here; for those you go north to the Similans/Richelieu or south to Hin Daeng.
- Phi Phi is a busy tourist hub; popular sites like the Bida islands see multiple day boats and can get crowded in high season.
- Koh Haa and the other Mu Ko Lanta park sites close for the southwest monsoon, mid-May to mid-October, so the winter-only Lanta options shrink to the year-round Bida and Phuket-side sites.
- Monsoon-season diving (May-October) still runs on the outer sites but means rougher crossings and more variable visibility.
- The King Cruiser is decaying — the upper decks have collapsed and penetration is unsafe — and current on the wreck and pinnacles can be moderate and unpredictable.
Sources & last checked
Checked July 2026
This is a researched draft, not yet human-verified. The seasonality and logistics are drawn from the sources below — confirm specifics (permits, fees, closures) with an operator before you book.
- Bida islands: Bida Nok, Nai & Hin Bida — Andaman Dive Adventure Lanta
- King Cruiser Wreck, Shark Point & Anemone Reef Fun Diving — Railay Dive Centre
- Koh Haa Diving: Dive Site Spotlight — The Junk
- Best Time of Year for Scuba Diving in Phi Phi Islands — Blue View Divers
- King Cruiser Wreck - Phuket Dive Sites — MV Giamani
- The Complete Guide to Koh Phi Phi Diving — The Midnight Blue Elephant
- Scuba diving Phuket, Phi Phi, Krabi and Koh Lanta — ZuBlu
Note on the data: Park-fee amounts (400-500 THB/park/day) come from operator pages and may have changed; flagged for verification against a current DNP source. Coordinates and bounding box are approximate area positions covering the Phi Phi, Lanta and Phuket-side outer sites, not surveyed GPS. Which specific sites fall under seasonal closure is the main uncertainty: Shark Point/Anemone Reef/King Cruiser are outside park boundaries and dive year-round; Koh Haa (Mu Ko Lanta park) closes mid-May to mid-October; the Bida islands sit in the Phi Phi park but are widely reported as diveable year-round, though some inner park zones close for reef recovery in mid-year. Water temperatures are interpolated from a seasonal range, not per-month measurements. Water temperature: Bands are approximate +/-0.5C around the ~28-30C the central Andaman holds year-round; occasional cooler upwellings can drop a single dive a degree or two below these surface figures. Access: Fly Phuket (HKT) or Krabi (KBV); day boats reach the sites in roughly 30-90 minutes, or ferry ~1.5-2h to a shore base on Phi Phi or Koh Lanta and dive from there. Independently verified 2026-07-20 (confidence medium).