The Khai Islands are three small rocky islands — Khai Nok, Khai Nai, and Khai Nui — sitting about 15 km east of Chalong in the sheltered waters between Phuket and the mainland. They're inside the Sirinath National Park extension (a branch of the Hat Noppharat Thara park system), which means there's a park entry fee, but it also means the reef has had some protection from the worst fishing and anchor damage.
None of the three islands is large — you could walk around any of them in 15 minutes. What they offer is shallow turquoise water around a fringing reef that's exceptionally easy to snorkel: 1–4m depth close to shore, calm water because they're in the inner bay, and good coral coverage relative to what's available this close to Phuket.
Khai Nok is the largest island and the one most group tours use. There are beach chairs, a restaurant, and toilet facilities. The reef on the northern and eastern side is the most accessible — entry directly from the beach into water that's waist-deep for 5–10m before the reef starts. Good for children who want to walk in rather than jump from a boat. The main downside: it's the most visited, so by 10am the beach is shared with multiple longtail loads of tourists.
Khai Nai is smaller, slightly less visited, and has better reef on its southern side. There's no restaurant here — just a small beach and the water. The coral around the southern headland is in noticeably better condition than Khai Nok's main area, likely because fewer people swim there. If you're on a private charter and your group snorkels, ask your captain to anchor at Khai Nai's southern side — it's one of those spots that most group tours skip entirely.
Khai Nui is the smallest island and essentially just a rocky outcrop with a small sand strip at low tide. It's worth circling by boat for the views and to snorkel the submerged reef around it, but there's no beach to land on. The waters between Khai Nui and Khai Nai have some of the best coral concentration in the group — a good swim for confident snorkelers.
Shallow reef (1–4m), calm water (sheltered inner bay), gradual beach entry, and crystal-clear visibility in good conditions combine to make this the most forgiving snorkeling environment near Phuket. Children who have never snorkeled before can stand up if they panic and the fish density is high enough to reward even a tentative first attempt. The flat water also means no seasickness on the crossing, which at 15 km takes 30–40 minutes even at moderate speed.
Khai and Coral Island are in the same general area — both south/southeast of Chalong, both easily reached in under 45 minutes. A private charter running both islands in one day is a popular option: snorkel the reef at Khai Nai in the morning, swing across to Coral Island for lunch and beach time in the afternoon. The transit between the two is about 30 minutes. This doubles the variety of your day without extending the trip length significantly.
| Boat type | Half day | Full day | Capacity |
|---|---|---|---|
| Speedboat (6–8 pax) | From ฿4,500–6,500 | From ฿7,000–9,500 | Up to 8 |
| Speedboat (12 pax) | From ฿6,500–8,500 | From ฿9,500–13,000 | Up to 12 |
| Power catamaran | From ฿14,000 | From ฿18,000–25,000 | Up to 20 |
Park fee (~฿300/adult) is additional and paid on arrival. Snorkeling equipment included in most private charters.
Because the Khai Islands sit in the sheltered inner bay between Phuket and the Phang Nga coast, they're accessible for much of the year. The sheltered position means even in the shoulder months (May, October) the water is calmer here than at Racha or Phi Phi. High season (November–April) is still the best period for visibility, but the Khai group is one of the more wet-season-friendly options on this side of Phuket.
Different, not better or worse in a simple sense. Khai Islands have shallower reef and are generally easier for absolute beginners — the reef starts closer to shore and the depth is very manageable. Coral Island's headland reef is slightly deeper (up to 8m at the headland) and has more variety for more experienced snorkelers. The water clarity is similar. Khai is also inside a national park so has slightly more protection.
Yes — the islands are close together and a private speedboat can cover all three in a full day easily, or two of the three in a morning half-day. The island-hopping between them adds maybe 10–15 minutes of boat travel each. Most private charters anchor at two locations and do a drift snorkel on the way between them.
Yes, always. The national park entry fee (~฿300 per adult, ฿150 for children under 14) is paid directly to the park authority on arrival, in cash. No charter operator can include this in a fixed package price because it's a government fee collected at the gate. Bring baht cash to the pier.
Better than most options. The inner bay position gives the Khai group some protection from the southwest monsoon swells. In June–September you'll get afternoon rain and possibly overcast skies, but the water often stays calm enough for snorkeling in the mornings. It's not as good as high season — visibility drops with rain runoff — but it's one of the more viable wet-season destinations near Phuket.
Khai Nok has a basic beach restaurant with Thai food and cold drinks — sufficient for a meal, not a gourmet experience. Khai Nai and Khai Nui have no facilities at all. For a full-day trip, arrange lunch provisions with your charter (most operators can supply a cooler with sandwiches, fruit, and drinks), or plan to eat on Khai Nok. If you're combining with Coral Island, there are better restaurant options on Coral's Long Beach.
Similar distance, more facilities on the beach. Pairs well with Khai Islands on a single charter.
View GuideFurther out (35 km), much better reef. The step up from Khai for more serious snorkelers.
View GuideLimestone karsts, sea caves, James Bond Island. A completely different experience from snorkeling islands.
View GuideGet available boats and prices for your dates.