How do you island hop in Indonesia?

Indonesia is 5,000 kilometres wide, which is the distance from London to Kabul. Island hopping here means choosing a corridor rather than a list.

The four sensible corridors

1. Bali, Lombok and the Gilis. Two to three weeks, short crossings, good infrastructure. The easiest multi-island trip in the country.

2. Bali to Flores along Nusa Tenggara. Bali, Lombok, Sumbawa, Komodo, Flores, with Sumba as a detour. Three weeks or more, flights and ferries, spectacular.

3. Java overland. Bali, Ijen, Bromo, Yogyakarta, Jakarta, by ferry and train. Two to three weeks and the best land travel in the country.

4. Sumatra. Lake Toba, Bukit Lawang, the west coast and the Mentawais. Two to three weeks, large distances, thin infrastructure.

Trying to combine two corridors in under a month means spending it in airports.

How you actually move

Domestic flights. The backbone. Garuda, Lion Air, Citilink, Batik Air and Wings connect everything, usually through Jakarta, Surabaya, Makassar or Denpasar. Cheap, frequent, and with baggage allowances that catch out surfers.

Fast boats. Bali to the Gilis and Lombok, Bali to the Nusas, Lombok to the Gilis. Comfortable-ish, weather-dependent, and variable on safety.

Public ferries. Slow, cheap, carry vehicles, run in weather that stops fast boats. Gilimanuk to Ketapang, Padang Bai to Lembar, Labuhan Lombok to Poto Tano, and the long Pelni routes that connect the whole archipelago.

Pelni. The national shipping line runs passenger ships on long routes across Indonesia. Slow, cheap, basic, and the most interesting way to travel in the country if you have weeks.

Trains. Java and parts of Sumatra only, and very good.

The rules that keep it working

Build in buffer days. Boats cancel, flights are delayed, ferries fill. One spare day per crossing.

Never connect a boat to an international flight on the same day. The most common way these trips go wrong.

Book domestic flights a few weeks out. They rise sharply close to departure and around holidays.

Watch the national holidays. Idul Fitri and the week around it is the largest annual human migration on earth. Everything is full.

Check the time zones. Indonesia has three. Java and Sumatra are an hour behind Bali; Papua is an hour ahead.

Cash. ATMs get unreliable the further east and the further from cities you go.

Malaria is present in much of eastern Indonesia and absent from Bali and most of Java. Take advice specific to your route.

A three-week route that works

Days 1 to 5: south Bali and the Nusas.

Days 6 to 10: Lombok, Kuta and Rinjani or the Gilis.

Days 11 to 12: fly Lombok to Labuan Bajo.

Days 13 to 16: Komodo by boat.

Days 17 to 20: overland Flores to Kelimutu.

Day 21: fly Maumere to Bali.

One direction, no backtracking, three flights.

A two-week route that works

Days 1 to 4: Bali.

Days 5 to 8: the Gilis and Lombok.

Days 9 to 13: fly to Labuan Bajo, Komodo boat trip.

Day 14: fly back to Bali.

Costs by corridor

Bali, Lombok, the Gilis. The cheapest. Boats 400,000 to 900,000 rupiah a crossing, accommodation 20 to 80 USD, and no flights needed.

Bali to Flores. Mid-range. Two or three domestic flights at 40 to 90 USD each, plus Komodo park fees and boat charters, which are the expensive part.

Java overland. The cheapest per day of anywhere in the country. Trains cost very little and guesthouses are 15 to 30 USD.

Sumatra and Raja Ampat. The most expensive, because the distances are large and the flights are long.

Packing for multiple islands

One bag you can carry onto a boat and up a beach. Dry bag for electronics because boat luggage gets wet. Cash in rupiah, because ATMs thin out fast. A basic medical kit, since pharmacies are scarce east of Lombok. And a phone with offline maps, because coverage is inconsistent once you leave Bali and Java.