Scuba diving in

Lembeh Strait

Located just off Sulawesi’s northeast coast, the narrow Lembeh Strait lies between the mainland and the island of Lembeh itself. The strait owes its famous diversity of species to a unique set of characteristics. First off, its location in the centre of the Coral Triangle means the surrounding seas are home to an incredible number of different marine species. But more importantly, Lembeh Island lies directly in the path of huge currents that connect the Indian to the Pacific Ocean. This stream of nutrient-rich, cooler water is channelled through the strait every day bringing with it a constant supply of food and juveniles of every sort - perfect conditions for an explosion of life.

Along its 14km length, Lembeh has sheltered bays and rocky pinnacles, black volcanic sand slopes, white limestone sand slopes, beds of algae, fringing coral reefs, rubble zones and even several shipwrecks. Man-made debris and sunken logs add to this array of different habitats, all contributing to the diversity of this remarkable spot. Although the term ‘muck-diving’ was first used to describe dive sites in Papua New Guinea, the Lembeh Strait’s unique environment means that the true home of critter hunting and exploring amazing underwater muck is in Sulawesi!

The closest airport for both international and domestic flights is Manado with frequent flights from Singapore as well as regular domestic flights from Jakarta and Bali via Makassar. From Manado, the transfer to Bitung by road takes an hour and a half, followed by a short 10 - 15 minute boat ride to your resort if you are staying on Lembeh Island.

Click here for more detailed information on how to get to Lembeh.

Gone are the days of a single dive resort in Lembeh with just 2 or 3 boats heading out to different sites every day. Today, diving in the Strait is big business and there are many resorts, passing liveaboards and day-trippers from Manado. Popular dive sites can be busy but the size of the strait means divers can normally find somewhere a little more peaceful.

The Lembeh Strait has dive resorts on the mainland, as well as along Lembeh Island’s west coast facing the strait. Guests can also choose to dive from Manado or Bangka on a day trip although, given the quality of diving in Lembeh, it makes more sense to stay in Lembeh if you are keen on doing some serious muck diving. With dive sites scattered up and down the strait, the resort’s all have similar access to the classic dives and visitors should base their choice of resort on budget, facilities on offer, and perhaps, access to a house reef.

Several resorts now offer combination packages allowing guests to dive the Bunaken National Park, Bangka Island and Lembeh Strait, all in one trip, making the transfers by boat rather than road and allowing guests to dive the best of North Sulawesi.

The strait’s protected location between the mainland and Lembeh Island means diving is great year-round - the seas are normally calm and dives sites with little or no current can always be found. The wet season runs from December to March, the dry season July to September, but you can expect some rain at any time of year. The visibility is at its lowest when the water is cool – normally in the summer months of August and September - but this pulse of cool water is great for critters and so while the visibility can be poor, the diving can be amazing from the summer and into October and November.

Many of Lembeh’s muck critters can be seen year-round and it is difficult to suggest a single best time of year to see something in particular. However, the dive resorts in the Lembeh Strait have studied their critter encounters and noticed some patterns. For instance, Lembeh Resort runs a useful ‘critter log’ with plenty of useful information. For example, whilst blue-ringed octopus can be spotted year-round, they are most often seen from August to December and carrying eggs from Jan to March. Mimic octopus are more likely to be seen mating from January to July. Flamboyant cuttlefish are seen feeding, mating and laying eggs year-round, but with a greater chance from August to January. If there is one time of year that seems to have more life than others, it is following the cold water months of July and August.

If you feel the cold, it is worth bringing a 5mm suit as dives are often quite long and slow. Currents are generally not a problem as the more exposed sites are avoided when the strong tidal flows are running through the strait. Water temperatures can drop to 25 - 26C in July and August, but are typically 27 - 29C.