- ✓This is the beach-and-island South on its own — no Bangkok deep-dive, no North. The first decision isn't where to go but which coast, because the Andaman and the Gulf are often wettest in different parts of the year.
- ✓Pick the Andaman (Phuket, Krabi, Phi Phi, Lanta) for roughly November to April; pick the Gulf (Samui, Phangan, Tao) for a period that is often more settled through much of January to September, although conditions vary. Match the coast to your dates and the islands almost choose themselves.
- ✓Keep your island-hopping within one coast. Crossing from an Andaman island to a Gulf island mid-trip is a full travel day across the peninsula — a relocation, not a hop.
- ✓Ten to fourteen days is the comfortable range: enough to base on two or three islands without spending half the trip on ferries and transfers.
- ✓Khao Sok National Park sits between the two coasts — rainforest and floating bungalows — so it's the natural green pause if you ever do want to cross from one sea to the other.
First decide the coast, not the islands
Southern Thailand is two beach worlds, not one, and they don't share their weather — so this route starts with a single decision that settles most of the others: which coast. The Andaman Sea in the west (Phuket, Krabi, Phi Phi, Koh Lanta, Khao Lak) is at its best in the cool, dry stretch from roughly November to April. The Gulf of Thailand in the east (Koh Samui, Koh Phangan, Koh Tao) usually has a later rainfall peak, generally good from around January to September with its heaviest rain typically later in the year.
That fact decides your whole trip. Travelling in, say, January or February? Either coast works, with the Andaman at its peak. Locked into June or July? The Gulf is the steadier bet while the Andaman is into its green season. Planning for October or November? The Andaman is reopening into its best run while the Gulf heads into its wettest. Pick the coast that fits your dates first, and the islands below fall into place.
Season is a planning guide, not a guarantee — rain may be brief or prolonged, so current warnings matter. But it does drive sea conditions and ferry reliability, which is exactly what makes or breaks a beach-and-boat trip. So settle the coast and the month before you fall for a specific resort, then run the matching day-by-day below.
Andaman · Days 1–3 — Phuket, the gateway and the Old Town
If you've chosen the Andaman, fly into Phuket — the coast's biggest hub, with the airport, every tier of hotel and easy boat access to the islands. Don't write Phuket off as just a resort strip: the Sino-Portuguese Old Town is genuinely worth a half-day, and the west-coast beaches make an easy first base while you find your feet. Three nights lets you arrive, swim, eat, see the Old Town, and run one island day trip.
Use one of these days for a boat trip to the limestone islands — Phang Nga Bay's karsts, or the Phi Phi islands if the season and seas allow — booking through a reputable operator and checking that trips are running, since green-season swells pause some of them. Base on the west coast for sunsets and beach time, or near the Old Town if you'd rather have the food and atmosphere on your doorstep.
Phuket is the practical launch pad rather than the highlight for many travellers, so treat it as the gateway block: arrive, acclimatise, run a boat day, then move to the prettier bases at Krabi and beyond. If your trip is short, you could even base the whole Andaman leg here and day-trip out — but the route below rewards spreading across two or three bases.
Andaman · Days 4–6 — Krabi, Railay and the Phi Phi day
From Phuket, move to Krabi — by road around the bay or by boat — and trade crowds for cliffs. Ao Nang is the convenient mainland base, while the boat-only beaches of Railay, hemmed in by limestone walls, are among the most beautiful in the country and reachable only by longtail. This is the Thailand of the brochures, and a couple of nights here is the scenic heart of the Andaman leg.
Spend the days island-hopping within the coast: the four-islands trip from Ao Nang, a longtail to Railay for the day, or a boat out to Koh Phi Phi if you didn't manage it from Phuket. Keep these as day trips or short hops within the Andaman — this is exactly the island-hopping the dedicated guide covers, and the rule is to stay on one coast rather than chase the Gulf islands now.
Krabi suits couples and scenery-seekers especially well, and it's an easy place to slow down. If you only have a week on the Andaman, Phuket plus Krabi is a complete trip; the next block is for those with ten days or more who want to end somewhere quieter.
Andaman · Days 7–10 — Koh Lanta or Khao Lak, the slow finish
For the back half of a longer Andaman trip, Koh Lanta is reachable by seasonal passenger boat or a year-round vehicle route using the mainland car ferry and Siri Lanta bridge. There is not yet a completed direct bridge from the mainland.
The alternative is Khao Lak, north of Phuket: a quieter resort strip backed by jungle, and the springboard for the Similan Islands' famous diving and snorkelling (a seasonal, Andaman-only run — check the park's open dates). Choose Lanta for slow island beach time, Khao Lak for diving and mainland comfort. Either makes a calm finish before you fly home from Phuket or Krabi.
That's the full Andaman arc: gateway, scenic heart, slow finish — three bases over ten days, every move within one coast. Resist adding a Gulf island onto the end unless you've built in the cross-peninsula travel day described below; otherwise you'll spend your best beach days in transit.
Gulf · Days 1–6 — Samui as base, then Phangan
If your dates suit the Gulf, the trio of Samui, Phangan and Tao is the mirror-image route with a different rainfall pattern. Fly into Koh Samui — the most developed of the three, with its own airport, full-service resorts and a family-friendly polish — or reach it by ferry from the Surat Thani mainland. Three nights settles you in: beaches, the Big Buddha, Fisherman's Village and easy resort comfort.
Then hop to neighbouring Koh Phangan by short ferry. It's famous for the Full Moon Party on Haad Rin, but just as much about quiet northern beaches, viewpoints and wellness retreats — so it suits both ends of the spectrum depending on the lunar calendar and where you base. Two or three nights lets you pick your side of the island: the party south or the calm north.
Keep the ferries in mind as the thing most worth nailing down — there's no bridge, so inter-island timing drives the whole Gulf leg. The Full Moon dates move each month, so if you're planning around (or away from) the party, check the schedule and book Phangan beds early; if you'd rather avoid it, the island's north stays peaceful even on party nights.
Gulf · Days 7–10 — Koh Tao and the diving finish
Cap the Gulf trip on Koh Tao, the smallest of the three and a major Thai budget dive-training hub, a short ferry on from Phangan. A huge share of visitors come here to learn to scuba, and the island is geared around it — but it's just as good for snorkelling, viewpoints and easy beach time if diving isn't your thing. Three or four nights covers a dive course or a string of relaxed days.
Tao is the natural turnaround of the Gulf route: from here you ferry back to Samui or Surat Thani to fly or train onward. As on the Andaman, keep the whole leg on one coast — Samui, Phangan and Tao are linked by frequent ferries and make a tidy three-island loop on their own season, no peninsula crossing required.
If you have only a week on the Gulf, Samui plus one of Phangan or Tao is a complete trip; the full trio is the ten-day version. Divers should weight the days toward Tao; beach-and-wellness travellers toward Phangan's quiet north and Samui's resorts.
Crossing coasts — Khao Sok is the bridge, not a shortcut
Sooner or later someone asks: can I do both coasts in one trip? You can, but only with the days for it — and Khao Sok National Park is the place that makes it civilised. Sitting between the Andaman and the Gulf, Khao Sok offers ancient rainforest, towering limestone cliffs and the floating bungalows of Cheow Lan Lake, and it slots neatly into a south-bound route as a green pause between sea and sea.
A worked cross-coast plan on two weeks might run: Andaman beaches → a couple of nights at Khao Sok → onward to the Gulf islands (or the reverse). That turns the dreaded peninsula crossing into a highlight rather than a lost travel day. But it's a relocation, not an island-hop: budget a full day of transfers around it, and only attempt it with fourteen days or more — on ten, commit to one coast and save the other for next time.
Whichever coast you choose, the shape is the same: pick the season, fly into the gateway, base on two or three islands within that one sea, and leave the crossing for a trip with the days to spare. Lock the peak-season hotels and any festival or dive dates first, and verify ferry status before you rely on a connection.
Sources and official planning resources
Southern Thailand route · at a glanceIsland FC
- Best season
- Andaman best Nov–Apr; Gulf often steadier Jan–Sep; check the forecast — pick the coast that matches your dates
- Ferry / flight access
- Fly into Phuket or Krabi (Andaman) or Samui/Surat Thani (Gulf); islands by ferry & speedboat
- Days
- 10–14 days to base on 2–3 islands within one coast without rushing the ferries
- Route shape
- One coast, gateway-then-islands; cross coasts only via Khao Sok with days to spare
- Best for
- Beach, scenery, diving and island-hopping travellers; couples and groups
- Sea / weather risk
- Rougher seas and paused boat trips in each coast's green season — verify ferry status
- Avoid if
- You want temples and culture as the focus — pair this with the North on a longer trip
