Krabi and Railay are the Andaman's limestone heartland: vertical karst cliffs streaked with stalactites, hidden lagoons inside the islands, and beaches so hemmed in by rock that you can only arrive by boat. Railay itself is a peninsula on the mainland, cut off from the road network by sheer cliffs, which is exactly why a yacht is the natural way to reach it. Lying roughly 30 to 40 km east of Phuket across open water, Krabi makes a rewarding private cruise: anchor below the cliffs of Phra Nang, drift into the enclosed lagoon of Hong Island, and walk the tidal sandbar of the Four Islands before the day boats arrive. This guide covers the best routes, what to see, when to go, how a day charter differs from an overnight trip, and roughly what it costs to charter a yacht or catamaran to Krabi and Railay.
Why explore Krabi and Railay by private yacht
Krabi's coastline is built for cruising. The scenery is the same dramatic limestone you find in Phang Nga Bay, but the islands are scattered across more open water, which rewards a boat that can move comfortably between anchorages and pick the calmest, quietest stops as the day unfolds.
Railay is the clearest case for going by sea. Walled off from the mainland by cliffs, the peninsula has no road access, so its beaches are reached only by boat. On a private charter you set the timetable, arriving at Phra Nang Cave Beach or the Four Islands early, before the longtails and ferries bring the crowds.
Catamarans are a favourite for the trip thanks to their wide, stable decks and shallow draft, which make swimming, kayaking and beach landings easy once you arrive. For larger groups or special occasions, a crewed motor yacht adds an air-conditioned saloon, shaded aft decks and the speed to spend more of the day among the islands rather than in transit.
Top sights around Krabi and Railay
Railay is the headline stop, a peninsula of four beaches framed by towering cliffs. Railay West has the soft sand and sunsets, Railay East is the mangrove side, and around the southern point lies Phra Nang Cave Beach, one of the most photographed beaches in Thailand, with its shrine cave and turquoise shallows beneath a sheer rock face. Tonsai, tucked just to the north, is the climbers' and backpackers' corner.
Hong Island (Koh Hong) is the other essential. Its name means 'room', and the island hides a near-enclosed emerald lagoon reached through a narrow gap in the cliffs, calm and shallow and ideal for a swim or a kayak. The surrounding beaches are powder-white and the water glassy on a still day.
The Four Islands, off Ao Nang, are the classic Krabi snorkel-and-swim circuit: Chicken Island (Koh Kai), Koh Tub, Koh Mor and Koh Poda. At low tide a sandbar known as the 'Separated Sea' rises from the water to link the three smaller islands, and you can walk between them on a strip of bright sand with the sea on both sides.
Day charter vs overnight
A full-day charter, typically eight to nine hours including the crossing, is enough to take in the marquee sights: Railay or Phra Nang, the Hong Island lagoon, a snorkel and swim at the Four Islands and lunch on board. This is the most popular format and the best value for a first visit.
An overnight charter transforms the trip. You stay out after the day boats have left, anchor in a sheltered bay for the night, and have Railay's beaches or the Hong lagoon almost to yourself at first light. Overnight itineraries also make it easy to combine Krabi with the islands of Koh Yao, with Phang Nga Bay to the west, or with a longer loop towards Phi Phi.
Because the run from Phuket to Krabi is an open-water crossing rather than the fully sheltered cruise into Phang Nga Bay, an overnight trip can also be the more comfortable choice in marginal weather, since you are not committed to a long return passage at a fixed time.
Suggested routes
Classic Krabi day trip: depart from Ao Po or a marina on Phuket's east coast, cross to the Hong Island lagoon for an early kayak, continue to the Four Islands for snorkelling and the sandbar walk, then anchor off Railay or Phra Nang for swimming and lunch before the return crossing.
Railay and Koh Yao overnight: the same start, then continue to anchor for the night near Koh Yao Noi or in a quiet Krabi bay, adding paddleboarding, a beach landing and a calm sunset beneath the cliffs before returning the next day.
Photographer's early start: leave at first light to reach Phra Nang Cave Beach and the Hong lagoon ahead of the day fleet, a plan that only works on a private charter where you control the timetable.
Best time to go
The high season runs from November to April, with the clearest skies and calmest seas from December to March. This is the most reliable window for the open crossing to Krabi and for snorkelling visibility around the islands.
The southwest monsoon, roughly May to October, brings more rain, wind and swell. The crossing can get choppy, so trips are run on calmer days and routes are adjusted to the conditions, favouring the more sheltered anchorages on the lee side of the islands.
If your trip also includes diving in the wider Andaman, note that the Similan Islands and the marine national park have a defined season, running only from about 15 October to 15 May, with the park closed during the monsoon. A Krabi cruise itself is not bound by those park dates, but it is still a weather-dependent open-water trip.
Combining Krabi with Andaman diving
The waters around Krabi are best known for relaxed snorkelling and easy swimming rather than serious diving. Guests chasing world-class reefs usually pair a Krabi cruise with a separate trip to the offshore sites, reached by liveaboard or day boat.
The standout is Richelieu Rock (5–35 m, intermediate to advanced), famous for seasonal whale-shark and manta sightings and best from February to April. The Koh Bon and Koh Tachai pinnacles (advanced, to around 40–45 m) are other Similan-area highlights for experienced divers.
For an easier introduction, the Boonsung Wreck off Khao Lak (13–20 m, beginner to intermediate) is a gentle reef-and-wreck dive. These offshore sites require the open-sea season, unlike the year-round day-trip appeal of Krabi and Railay.
How much does it cost
Prices vary with the size and style of boat, the season and the day's length, so treat the following as realistic retail starting points for a private charter rather than fixed quotes. The open crossing to Krabi also means fuel is a bigger factor than for the sheltered run into Phang Nga Bay.
A sailing or cruising catamaran for a full-day Krabi charter typically starts from around 20,000 THB for the whole boat, making it strong value for a family or small group, while a larger sport or luxury catamaran generally starts higher. A fast speedboat, which cuts the crossing time, usually starts from about 65,000 THB for the day.
Crewed motor yachts run higher: a classic or mid-size motor yacht for a full day usually starts from around 50,000 THB upward, while premium flybridge and sport yachts begin higher again. Overnight charters are priced per night and include crew; final figures depend on cabins, catering, fuel and route, so we quote each itinerary individually.
Featured vessels for this trip
Estrella · Leopard 43
Blue Wings · Lagoon 440
Blue Castle · Lagoon 420
Grand Banks 53ft "Sambuca"
Seascape 2 · Sunseeker Manhattan 60
Mami Wata · Halvorsen 1954Frequently asked questions
How far is Krabi from Phuket by yacht?
Krabi lies roughly 30 to 40 km east of Phuket across open water. The crossing takes about an hour and a half to two and a half hours on a cruising motor yacht or catamaran, or around forty-five minutes on a fast speedboat, so it is a longer and more exposed trip than the sheltered cruise into Phang Nga Bay.
Can I reach Railay only by boat?
Yes. Railay is a peninsula on the mainland, but sheer limestone cliffs cut it off from the road network, so there is no land access. Its beaches, including Phra Nang Cave Beach, are reached only by boat, which makes a private charter the natural and most comfortable way to visit.
What is the 'Separated Sea' at the Four Islands?
It is a sandbar off Ao Nang that emerges at low tide and links Chicken Island, Koh Tub and Koh Mor. When the tide is right you can walk between the islands on a strip of bright sand with sea on both sides. A private charter lets your captain time the visit around the tide.
Day trip or overnight to Krabi: which should I choose?
A full day covers the main sights and is the best value for a first visit. An overnight charter lets you enjoy Railay and the Hong Island lagoon after the day boats leave, watch the sunset beneath the cliffs and combine Krabi with Koh Yao or Phang Nga Bay, and it can be more comfortable than a fixed-time return crossing in marginal weather.
Is there good diving and snorkelling around Krabi?
Krabi is excellent for relaxed snorkelling and swimming around islands such as Koh Poda and the Four Islands, but its local diving is modest. For world-class reefs such as Richelieu Rock (5–35 m, best February to April), guests usually add a separate offshore liveaboard or day trip.
How much does a Krabi yacht charter cost?
As a guide, a cruising catamaran for a full day starts from roughly 20,000 THB for the whole boat, a fast speedboat from about 65,000 THB, and crewed motor yachts from around 50,000 THB upward, with larger luxury yachts higher again. Overnight rates are quoted per itinerary.