Koh Larn isn't remote, but the quieter beaches have almost no shops, and even the busy ones charge island prices for anything you forgot. Pack a sensible day-bag on the mainland and you'll have a smoother, cheaper day. Here's the exact list, honed over many crossings.

The essentials (don't skip these)

  • Cash in small notes — the ferry, songthaews, loungers and most food are cash-only, and island ATMs charge foreign-card fees. Withdraw on the mainland.
  • Reef-safe sunscreen — strong tropical sun, and kinder to the water you're swimming in.
  • Water and a hat — shade and shops are thin on the quieter beaches.
  • A rash guard or light long-sleeve top — better sun cover than constant re-applying, plus some jellyfish protection in the monsoon.
  • Your phone in a dry bag — protects it on the boat and the banana ride.

Highly recommended

  • Your own snorkel mask — better fit and hygiene than rentals, and it's free snorkeling.
  • Water shoes — several beaches have rocky entries and the sand gets hot.
  • A quick-dry towel and a change of clothes for the ferry home.
  • Basic first-aid bits — plasters, antiseptic; the quiet beaches have nothing.
  • A power bank — you'll use the camera and maps all day.

Nice to have

A pop-up sunshade or beach tent if you want guaranteed shade beyond a rented umbrella; motion-sickness tablets if speedboats bother you; a small cool bag for drinks if you're settling in for the day; and insect repellent for dusk if you're staying late or overnight.

What to leave behind

Your passport (carry a photocopy — never leave the original as a rental deposit), anything valuable you'd hate to lose on a beach, and heavy luggage if you're day-tripping. Travel light; you'll be carrying it over sand and possibly up a hill.

Tip: Wear your swimwear under your clothes so you're in the water minutes after landing — and pack the dry clothes for the journey back, not the way out.

The verdict

Cash, sun protection, water, a dry bag and a mask cover 90% of it. Get those right and the island can't catch you out. More in our practical guide and start-here guide.