'Muck' Diving in Lembeh StraitLembeh Strait is undoubtedly a special place in terms of diving. What is considered rare elsewhere is relatively common here, including critters such as hairy frogfish, mimic octopus, mandarin fish, devilfish, flamboyant cuttlefish, ghost pipefish, pygmy seahorses and much much more….
There is a tremendous variety of frogfish, venomous fish, snake eels, crustaceans and nudibranchs, with every dive offering an opportunity to find a species new to science. There’s something here for everyone, even the most jaded of divers.
It is important to note that dive sites can seem overflowing with critters for a month or two and then seem devoid of inhabitants for a period of time. What we see on our dives is for the most part seasonal. There can be multiple ornate ghost pipefish on numerous sites at one time and a few weeks later none at all to be found. We have not spotted any juvenile zebra batfish for months on end and then have found five simultaneously on different dive sites. A few distinct species of nudibranch can seem to infest certain sites for a few weeks and then all disappear for a different set of nudis to follow. Some months can have frogfish or octopus seemingly everywhere in abundant numbers, but the same month a year later can have few. We survey new areas and check out-of-use sites methodically to determine which areas are the most fruitful.
The Incredible Biodiversity in Lembeh
Why are these waters so rich? It most probably is no coincidence that the largest water movement on the planet, known as the Indonesian Throughflow, splits past the northern tip of Sulawesi. To the north of Sulawesi, a string of volcanic islands form a chain all the way to the island of Mindanao in the Philippines. Below the water this chain forms the Sarangani Sill, which divides deepwater basins to the east and west.
To the west of Sulawesi is the Sulawesi Basin, while to the east there is the Philippine Sea and the West Caroline Basin. The movement of water westwards from this basin begins the Indonesian Throughflow. Hitting the Sarangani Sill, the shallow portions of this water flow over this barrier and continue westward and down the west coast of Sulawesi. The deeper waters hit the barrier and are diverted southward down the eastern side of Sulawesi and through the Moluccan Islands. Most of North Sulawesi lacks a continental shelf, which means that abyssal depths exist directly offshore and these deeper, nutrient-rich waters are forced upwards and churned with surface waters as they are flushed through the narrow confines of the strait.
Though currents are strong in the main channel, there are numerous small bays out of the current stream suitable for easy diving in which the nutrients settle to foster the rich biodiversity that our region is renowned for.
Our Diving Day
All of our boat dives are out-and-back, so you are not obligated to do two morning dives if you do not wish to. Sleeping in with a late breakfast is a viable option. The first boat dive of the day is at 8:00, with coffee/tea and a snack awaiting at the Dive Center on your return. The second boat dive departs at 11:00. We ask or guests to limit their bottom time to 75 minutes on boat dives so that we can keep to our schedule and ensure safe surface interval times.
Our staff will help with your equipment, cleaning it and hanging it up for you in your equipment locker at the end of your diving day. The next morning they will have your bcd and regulator set assembled and ready aboard the boat. If doing a self-guided beach dive, we do ask you to rinse and store your equipment yourself.
Diving Conditions in Lembeh Strait
The water is generally cool for the tropics, averaging 28 degrees Celsius (82 degrees F). With this in mind, full wetsuits are recommended to conserve body heat on the multiple dives done daily, which are usually shallow, meaning long. We do get colder thermoclines moving in from time to time, which is beneficial as cold upwellings spur mating cycles in pipefish, nudibranchs and other species.
The visibility is also less than many dive destinations on average, owing to the nutrients in the water that are the reason for the wealth of biodiversity. Visibility averages 10-15 meters, though it can be somewhat less or as good as 30 meters.
Right off our beach is some of the best diving in Lembeh Strait. The established dive sites of Hairball 3, TK1 and TK2 are literally at your doorstep. With two paid boat dives daily, guests can take a tank and have a free self-guided House Reef dive while guests on 3-dive / day packages have unlimited access. We allow solo diving on the House Reef at the discretion of the Dive Manager, though guides can be booked on request to help get the most out of our front yard, depending on availability. Because of a lack of currents, it can be safely dived at any time, and it is at night that it is especially incredible.
All of the iconic muck critters are regularly encountered: frogfish (nine species, possibly more), octopus (mimic, wonderpus, ocellated, white-v, brown mimic, reef, algae and even the two species known generically as “hairy octopus”), squid, cuttlefish (including flamboyant cuttlefish), Rhinopias (both the frondosa and eschmeyeri species have been seen, but are considered quite rare), bubble shells, spanish dancers and far too many more nudibranch species to list, stargazers, various waspfish, ghost pipefish (robust, delicate, velvety, ornate and filamented), pipehorses, sea horses, bamboo and coral cat sharks, heaps of banggai cardinalfish, flying gunards and fingered dragonets, juvenile clown sweetlips and barramundi, an incredible variety of lionfish and scorpionfish species, numerous snakes, moray and ribbon eels, rays, crustaceans galore and much more. There is so much to see in the shallows that divers usually never even reach 15 meters in depth.
Dr. Gerry Allen called our House Reef “Shrimp Goby Heaven”.
With this much to see in such easy conditions directly off our beach, divers can be assured of getting what our beloved friend Larry Smith would call “Maximum Critter Overload” and photographers can have all the time they wish to get that elusive perfect shot.
What Every Dive Resort Should Strive to Be
"This was a phenomenal dive trip and we will be back here on our next visit to Lembeh. Thanks again to Bruce, Fung, and all of the wonderful staff who made our vacation a fantastic one!"
Scallywag81 on TripAdvisor
Three times is not enough...
"In the 20+ years that we've been diving, in about the same number of different countries, there was only one other place where we went back a second time. But Black Sand? Oh we just couldn't stay away!"
Katrien V on TripAdvisor
Idyllic Resort Set in Middle of Lembeh’s Best Diving
"Bruce was often present at meal time, and he is a wealth of knowledge about all things diving, especially Lembeh and critter identification. We really enjoyed our discussions with him. The dive staff was outstanding."
Doug F on TripAdvisor
Missing it Already and Can't Wait to Return!
"We visited Black Sand for the second time because we could not have imagined having better hosts than Bruce and Fung as well the number and variety of great dive sites."
Brown C on TripAdvisor
Black Sand Dive Retreat
Kel. Kasawari, Bitung
North Sulawesi, Indonesia
Tel: 62 (0)821-9969-5992