Similans in a day: the 06:15 pickup, Elephant Head, and Sail Rock at four

Khao Lak, Similan Islands

1. 6:15 am1

   Hotel pickup on the Khao Lak beach roadKhao Lak

   The minibus loops the beach road and you are first or last depending on where you sleep — staying at Nang Thong buys you an extra twenty minutes in bed. Nothing is open for breakfast at that hour anywhere in Khao Lak; the boat feeds you at 08:30, so do not go hunting.

2. 7 am2

   Check in and kit up at Thap Lamu PierKhao Lak

   Roughly 4,900–6,100B for the two-dive day trip with gear, lunch and transfers, and some centres price the midweek departures lower. Bring the physical certification card — a couple of shops still refuse a photo of it. Give your wetsuit and fin size at booking, not at the pier: the common sizes are gone by 07:20.

3. 8 am3

   Speedboat out to Mu Ko SimilanSimilan Islands

   700B national park fee, cash, collected on the boat — nobody mentions it when you book and there is no ATM at Thap Lamu. Sit at the back if you get seasick; with any swell it is an hour of slamming, and the crossing is the worst part of an otherwise perfect day.

4. 9:45 am4

   Dive one: Elephant Head RockSimilan Islands

   Granite boulders the size of houses stacked into swim-throughs and chimneys. Current runs here, so it is a follow-the-guide dive rather than a wander — stay off the rock, let it push you through the gaps, and keep the guide's fins in sight through the narrow bits.

5. 11:15 am5

   Thai buffet lunch on the boatSimilan Islands

   Cooked on board and included in the trip price. Eat the rice even if you feel queasy — the surface interval is 90 minutes and the second dive is the deeper one of the day.

6. 1 pm6

   Dive two: Christmas Point, Island 9Similan Islands

   Bigger boulders, more open blue, and the day's best chance of leopard sharks lying on the sand at the reef edge. It runs deeper than the morning dive, so hold gas back rather than chasing the first thing you see.

7. 2:30 pm7

   Donald Duck Bay and the climb to Sail RockSimilan Islands

   Fifteen sweaty minutes of boardwalk and boulder to Sail Rock, which is the view the Similans are on postcards for. Landing rules change every season and Island 8 closes with no notice when visitor caps bite — ask the guide on the boat that morning, not a blog from last year.

8. 6:15 pm8

   Back at Thap Lamu, dinner within walking distanceKhao Lak

   You will be salt-crusted, sunburnt and asleep by 21:00. Choose somewhere you can walk to from the room rather than somewhere good — this is not the night to plan a taxi.