Satonda Island is a tiny stop off Sumbawa's north coast built almost entirely around one feature: a saltwater lake sitting inside the crater of an old volcano, separated from the sea outside by nothing more than a narrow rim of land. It is one of the shortest excursions on a Sumbawa itinerary, and one of the most talked about afterwards.
What makes Satonda Island unusual
The lake inside Satonda's crater is saltwater, not fresh, even though it has no visible channel connecting it to the ocean, with seawater believed to seep through the porous volcanic rock that forms the crater wall. Sitting inside a lake with no open link to the sea, surrounded by jungle on one side and a beach on the other, gives the place an odd, contained feeling that is different from anywhere else on a typical Sumbawa stop. The island itself is uninhabited and protected as a nature reserve, so beyond the path to the lake there is little sign of development, which suits a quick, self contained stop rather than a long shore excursion.
The lake's limestone formations
Divers and snorkellers who go into the lake have noted unusual limestone growths beneath the surface, coral like in shape despite forming in a landlocked body of water with no direct connection to reef outside. It is the kind of detail that makes a short stop here worth the walk, even for guests who have already spent days snorkelling proper reefs elsewhere on the trip. The lake's isolation from the open sea, combined with its volcanic origin, has given it a slightly different chemistry and ecosystem from a normal coastal lagoon, which is part of why researchers as well as travellers have taken an interest in Satonda over the years.
Getting from the beach to the lake
Yachts anchor off Satonda's beach, and the lake itself is a short walk inland through light forest, easy enough for most guests and quick enough to fit into a half day stop alongside another nearby destination. There is no infrastructure beyond a simple path, in keeping with how lightly visited this stretch of coast still is. Bring water and reasonable footwear for the short walk, and expect to be back at the beach, and back on the tender, well within an hour or two depending on how long you spend swimming.
Why Satonda draws scientific interest
Because the lake sits inside a sealed volcanic crater with only slow seepage connecting it to the sea, it behaves differently from an open lagoon: temperature, salinity and the life inside it can vary with depth in ways a normal coastal inlet does not show. Researchers have studied lakes like this one for exactly that reason, as a small, contained example of how isolated water bodies develop their own conditions over time, and it is worth knowing that context even if your own stop is a short swim rather than a scientific visit.
Swimming in the crater lake
The lake is generally calm and shallow near the edges, a contrast to the open water sailing that fills most of a Sumbawa itinerary, and a swim here is usually a quiet, standalone experience rather than part of a longer excursion. Bring reef safe sunscreen and expect no facilities beyond what your own yacht provides. Given the lake's enclosed nature, it is also a sensible spot to rinse off gently rather than treat it as an open swimming pool, since whatever goes into the water stays in that same small, contained body for a long time.
Fitting Satonda into your itinerary
Satonda sits close to Moyo Island, and the two are almost always visited on the same leg of a charter that sails from Bali toward Komodo. Our Moyo Island guide and Sumbawa by yacht overview cover how this stretch of coast usually fits into a longer route, alongside a stop for whale sharks in Saleh Bay. Most itineraries pair Satonda with Moyo on the same day, given how close the two anchorages sit to each other.
Plan your charter
If you want Satonda's crater lake on your route, mention it when you send us your dates and we will build it into a Sumbawa to Komodo itinerary. Send your dates or see which yachts are open for the current board.
Frequently asked questions
Why is the lake inside Satonda salty?
Seawater is believed to seep through the porous volcanic rock forming the crater wall, keeping the lake saline even without a visible channel to the ocean outside.
Can you swim in Satonda's crater lake?
Yes. It is generally calm and shallow near the edges, and swimming in the lake is one of the main reasons charters stop here.
How far is the walk to the lake?
A short walk inland from the beach through light forest, manageable for most guests in normal footwear and quick enough for a half day stop.
Is Satonda usually combined with Moyo Island?
Yes. The two sit close together off Sumbawa's north coast and are almost always visited on the same leg of a Bali to Komodo sailing itinerary.
Is Satonda suitable for children?
Generally yes. The walk is short and the lake itself is calm, though as with any open water swim, children should be supervised and comfortable in the water beforehand.
Does anyone live on Satonda?
No. The island is uninhabited and protected, with no permanent settlement, which is part of why it has stayed so undeveloped despite sitting close to a popular sailing route.