Sumbawa is a large island in Indonesia's West Nusa Tenggara province, between Lombok and Komodo National Park. It is home to Mount Tambora, whose 1815 eruption was the largest in recorded history, plus the forest and waterfalls of Moyo island, Satonda's crater lake, year-round whale sharks in Saleh Bay and the surf at Lakey Peak.
Most travellers fly over it on the way to Labuan Bajo. Those who sail past it instead, on a yacht from Bali to Komodo, find a quieter, drier and much less visited island with a few sights that rank among the most unusual in the country. This guide covers the island as a whole, what to see, how to get there, the best time to go, and how a Sumbawa leg fits into a Komodo charter.
Quick facts
| Fact | Detail |
|---|---|
| Location | Lesser Sunda Islands, between Lombok to the west and Komodo and Flores to the east |
| Province | West Nusa Tenggara (Nusa Tenggara Barat) |
| Area | About 15,448 square kilometres |
| Main towns | Sumbawa Besar in the west, Bima in the east |
| Highest landmark | Mount Tambora, inside Tambora National Park (established 2015) |
| Protected areas | Tambora National Park; Saleh Bay, Moyo and Tambora form a UNESCO biosphere reserve (2019) |
| Getting there | Flights to Bima or Sumbawa Besar; car ferry from Lombok; or by yacht from Bali |
| Best months | The dry season, roughly May to October |
| Highlights | Tambora, Moyo, Satonda, Saleh Bay whale sharks, Lakey Peak |
| By yacht | Usually two or three days on a route between Bali and Labuan Bajo |
Where is Sumbawa, and what is it like?
Sumbawa is one of the Lesser Sunda Islands, in the west-central part of West Nusa Tenggara province, with an area of about 15,448 square kilometres according to Britannica. Lombok lies across a narrow strait to the west; to the east lies Komodo National Park, which UNESCO places between Sumbawa and Flores.
The island is long and irregular, with Saleh Bay, its largest bay, cutting deep into the north coast. Administratively it is split between several regencies, including Sumbawa in the west and Dompu and Bima in the east. Inland, much of it is dry, rolling hill country, quite different in feel from the green rice terraces of Bali, with long empty coastlines and very few foreign visitors.
Mount Tambora and the 1815 eruption
Mount Tambora, on Sumbawa's northern Sanggar peninsula, erupted in April 1815 in the largest volcanic eruption in recorded history. The eruption began on 5 April and peaked on 10 April, was rated 7 on the Volcanic Explosivity Index, and cut the mountain from about 14,100 feet to just under 10,000 feet, according to NOAA.
| Tambora 1815 | Figure (source: NOAA) |
|---|---|
| Eruption dates | Began 5 April 1815, peaked 10 April |
| Volcanic Explosivity Index | 7 |
| Height before and after | About 14,100 feet to just under 10,000 feet |
| Ash ejected | Roughly 31 cubic miles |
| Deaths from pyroclastic flows | About 11,000 |
| Deaths from later food shortages | More than 100,000 over the following decade |
The ash cloud spread around the Northern Hemisphere and average temperatures there dropped by about one degree Fahrenheit, NOAA says. The result was 1816's "year without a summer", with crop failures and food shortages across North America, Western Europe and parts of Asia. Estimates of the total death toll vary between sources, so treat any single figure as an estimate.
Today the mountain sits inside Tambora National Park, established by a ministerial decree dated 7 April 2015 and covering about 71,645 hectares, according to Indonesia's Cabinet Secretariat. Tambora already holds national geopark status, and West Nusa Tenggara's provincial government put it forward for UNESCO Global Geopark recognition in 2026, as Detik reported. Climbing it is a multi-day trek in its own right, separate from a yacht trip, but from the water you can see the vast, flattened summit rising behind the coast.
Moyo island
Moyo is a forested island off Sumbawa's north coast, at the mouth of Saleh Bay, and the main reason to stop is a walk inland to the tiered pools of the Mata Jitu waterfall. Much of the island is protected, and its reputation as a hideaway grew after Princess Diana visited, as Detik recounts.
In 2019, UNESCO recognised Saleh Bay, Moyo and Tambora together, known by the short name Samota, as a biosphere reserve, as Mongabay reported. Our Moyo Island guide covers the walk and the island in detail.
Satonda's crater lake
Satonda is a small volcanic island off Sumbawa's north coast with a lake filling its crater, a short walk from the beach. The lake is salty and stratified, with brackish water on top, and scientists study it because it contains living, calcifying microbial reefs called stromatolites, a rare window onto how early oceans may have worked.
Research published in Facies describes how the lake started as fresh water, later filled with seawater, and how ash from the 1815 Tambora eruption altered its chemistry. For a yacht, Satonda is an easy half-day stop, usually paired with Moyo. Our Satonda crater lake guide has more.
Whale sharks in Saleh Bay
Saleh Bay is the large, semi-enclosed bay on Sumbawa's north-central coast, opening onto the Flores Sea, and it is one of only two bays in Indonesia known to host whale sharks year-round. A decade-long satellite tracking study of 70 whale sharks, published in Frontiers in Marine Science in April 2026, identified Saleh Bay and Cenderawasih Bay as the two, according to Conservation International.
The sharks gather around bagan, the traditional lift-net fishing platforms whose lights draw in small fish. Researchers have also recorded newborn whale sharks in the bay, which suggests it may serve as a nursery. Saleh Bay is recognised as an Important Shark and Ray Area, and Konservasi Indonesia is working with communities and government on what would be Indonesia's first whale shark-focused marine protected area there.
Sightings are never guaranteed, and an IPB University study has raised concerns about the effect of tourism on the sharks' welfare, so a good operator keeps distance, limits numbers in the water and never touches or feeds them. It is a snorkelling encounter, so it suits most guests. Our Saleh Bay whale shark guide explains how a morning at the platforms works.
Surfing Lakey Peak
Lakey Peak, at Hu'u in Dompu on Sumbawa's south coast, is one of Indonesia's best-known surf breaks: a fast, hollow A-frame that breaks both left and right. The main surf season is the dry season, roughly May to October, when southwest swells meet easterly trade winds blowing offshore, according to Surf-Forecast.
It is on the opposite side of the island from Moyo, Satonda and Saleh Bay, which are on the north coast, so a north-coast yacht route does not pass it. Surfers usually reach it by road from Bima or on a dedicated surf trip.
How do you get to Sumbawa?
You can fly, take the ferry from Lombok, or arrive by sea on a yacht. Sumbawa has two main airports: Sultan Muhammad Salahuddin airport at Bima in the east and Sultan Muhammad Kaharuddin airport at Sumbawa Besar in the west.
- Fly to Bima: TransNusa launched a non-stop Denpasar to Bima service in December 2025, running daily from 22 December, according to Antara. Check current schedules, as regional routes change.
- Take the ferry from Lombok: car ferries cross from Kayangan on Lombok to Poto Tano on Sumbawa many times a day; on one busy day before Lebaran in March 2026 there were 41 crossings, Detik reported.
- Sail from Bali: a yacht charter between Bali and Labuan Bajo can stop along Sumbawa's north coast for two or three days.
For most visitors, the sights that matter, Moyo, Satonda and Saleh Bay, are easiest to reach by boat, which is why the yacht route is the most practical way to see them together.
When is the best time to visit Sumbawa?
The best time to visit Sumbawa is the dry season, roughly May to October. Rain is scarce, seas along the north coast are generally settled, and it is also the main surf season at Lakey Peak. Indonesia's weather agency, BMKG, expected the 2026 dry season to peak in August across almost all of West Nusa Tenggara, as Metro TV reported.
| Months | Sumbawa conditions |
|---|---|
| May to June | Dry season begins, hills still green, surf season starts |
| July to August | Peak dry season, very little rain |
| September to October | Still dry, landscape brown and gold |
| November to April | Wet season, more rain and less settled seas |
Whale sharks are present in Saleh Bay year-round, so the season matters more for the sailing than for the sharks. Our best time for a yacht charter in Indonesia puts Sumbawa in the context of the whole region.
Sailing Sumbawa on the way to Komodo
A Sumbawa leg turns the trip to Komodo into part of the holiday rather than a flight. Instead of flying from Bali to Labuan Bajo, you board in Bali and sail east, stopping at Moyo's waterfall, Satonda's crater lake and the whale shark platforms of Saleh Bay before crossing into Komodo National Park. Some operators also run the route the other way.
The three north-coast stops sit within a day's sailing of each other, so they are usually grouped. A typical pattern is the walk to Mata Jitu on Moyo in the morning, a swim in Satonda's crater lake in the afternoon, and a short sail into Saleh Bay to anchor near the fishing platforms, ready for the whale sharks early the next morning. Your captain sets the exact order around wind, tides and where the platforms are working.
Allow seven nights or more if you want both Sumbawa's highlights and proper time inside Komodo, because the sailing distances add real days. With less time, most guests choose Saleh Bay's whale sharks plus one of Moyo or Satonda rather than rushing all three. Sumbawa is a few days' extension to a Komodo trip; it is not a separate charter region in its own right.
Three boats on our board list Sumbawa among their regions, Augustine, Ikan Kayu and Magia II, all phinisis, with whole-boat rates from about US$3,900 to US$5,900 a night. Our Bali to Komodo by flight or boat guide compares the two ways in, and our Lombok to Komodo boat trip covers a shorter version. When you are ready, browse the fleet or send your dates and our concierge will check which boats are running a Sumbawa route that season.
Frequently asked questions
Where is Sumbawa in Indonesia?
Sumbawa is in the Lesser Sunda Islands, in West Nusa Tenggara province. It lies east of Lombok and west of Komodo National Park and Flores. It covers about 15,448 square kilometres, and its main towns are Sumbawa Besar in the west and Bima in the east. Its north coast is on the sailing route between Bali and Labuan Bajo.
What happened when Mount Tambora erupted in 1815?
Tambora's eruption in April 1815 was the largest in recorded history, rated 7 on the Volcanic Explosivity Index. According to NOAA, it killed about 11,000 people directly, and more than 100,000 died from food shortages over the following decade. The ash cooled the Northern Hemisphere, causing 1816's "year without a summer".
Can you see whale sharks in Sumbawa all year?
Saleh Bay is one of two bays in Indonesia where research shows whale sharks are present year-round, based on a decade-long tracking study published in 2026. They gather around the bagan fishing platforms at night and in the early morning. Sightings are never guaranteed, and responsible operators limit swimmers and keep their distance.
How do I get to Sumbawa from Bali?
You can fly from Denpasar to Bima, which TransNusa began serving non-stop in December 2025, or travel overland through Lombok and take the car ferry from Kayangan to Poto Tano. On a yacht charter, you can sail from Bali along Sumbawa's north coast and continue to Komodo National Park.
Is Sumbawa worth visiting?
Yes, if you want something quieter than Bali or Komodo. It has a volcano with a world-changing history, a waterfall island, a crater lake with living stromatolites, year-round whale sharks and a famous surf break, with very few foreign visitors. By yacht, it adds two or three memorable days to a Komodo trip.
What is the best time to visit Sumbawa?
The dry season, roughly May to October, is best: little rain, settled seas along the north coast and the main surf season at Lakey Peak. BMKG expected the 2026 dry season to peak in August across West Nusa Tenggara. The wet season, roughly November to April, brings more rain and less settled conditions.
How many nights do I need to include Sumbawa on a Komodo charter?
Plan on seven nights or more for a charter that covers Sumbawa's north coast and gives proper time to Komodo National Park. Moyo, Satonda and Saleh Bay sit close to each other, but the sailing from Bali and on to Komodo takes real time. With fewer nights, choose one or two Sumbawa stops.
Is Lakey Peak on the yacht route?
No. Lakey Peak is at Hu'u in Dompu on Sumbawa's south coast, while Moyo, Satonda and Saleh Bay, the usual yacht stops, are on the north coast. Surfers normally reach Lakey Peak by road from Bima, ideally in the dry season when southwest swells and offshore trade winds line up.
Sources
- Sumbawa, Britannica
- Komodo National Park, UNESCO World Heritage Centre
- This day in history: Mount Tambora explosively erupts, 1815, NOAA NESDIS
- Presiden Jokowi resmikan Taman Nasional Gunung Tambora, Sekretariat Kabinet RI
- Kawasan Tambora NTB diusulkan jadi geopark dunia, Detik
- Ketika Teluk Saleh, Moyo dan Tambora jadi cagar biosfer dunia, Mongabay
- Pernah dikunjungi Putri Diana, keindahan Pulau Moyo, Detik
- Microbialites and hydrochemistry of the crater lake of Satonda, Facies
- Decade-long whale shark study highlights need to protect broader habitat, Conservation International
- Whale shark tourism in Saleh Bay, IPB University repository
- Lakey Peak surf guide, Surf-Forecast
- Kota Bima dan Denpasar segera terhubung dengan pesawat jet regional, Antara
- Arus mudik di Pelabuhan Kayangan Poto Tano, Detik
- BMKG prediksi puncak kemarau di NTB terjadi Agustus 2026, Metro TV