Adelaar Cruises
Contributor
Pulau Sangeang – Diving Between Bali and Komodo
Located outside Komodo National Park, this volcanic island is a must do on any dive liveaboard traveling from Bali or Bima. Although volcanic, with black sand, Sangeang isn’t normally considered a traditional “muck” area. Fantastic muck diving is available, but Sangeang is so much more! The most diverse of the sites there, and the one at the top of my list, is Hot Rocks (aka Bubble Reef).
Colors Pop at Hot Rocks
Diving off the flank of an active volcano can be amazing, but diving Hot Rocks at the base of Sangeang’s twin peak volcano is surreal! You’ll often find great black sand critter diving around volcanoes, but at Hot Rocks you can find everything from a field of bubble streams that reminds you of champagne bubbles, to hot water vents coming from the earth’s core, to a variety of glorious neon green and orange black coral bushes covered in Golden Sweeper fish. Those are in addition to a plethora of creatures and colorful reef fish. Add all these stimulating visuals together on one dive and you’ll see why the Colors Pop at Hot Rocks.
Pink sea anemone
Amidst a field of black sand and bubbles, are rocks and boulders covered with marine life. There are soft corals with Candy crabs, sea fans with pygmy seahorse, tunicates and yellow cup corals that make an ideal environment for frogfish, leaf scorpion fish and nudibranch to hide and feed. Together with the usually warm blue water your eyes will be treated to a dazzling spectacle of underwater sea life at its most colorful.
Photo by: Reinhard Dirscherl
As you can see from the photo at the very top (by: Fred Bavendam), in places gaseous sulfur is seeping out from the ground, creating an underwater Jacuzzi with a warm sea floor! Around Sangeang and throughout Indonesia’s “Ring of Fire” there are a number of dive sites have these underwater hot springs. Water is heated by geothermal activity within the earth’s crust and this water is pushed out through a hydrothermal vent. The vent is a fissure in the planet’s surface from which geothermally heated water escapes.
Hydrothermal vents exist because the earth is both geologically active and has large amounts of water on its surface and within its crust. The area around submarine hydrothermal vents often attracts a diverse group of critters and that makes it a perfect place to see cool things.
Burying their dive computers under the sand, divers in North Sulawesi measured 41C (106F) water temperature at their local hot spring while the surrounding water was 29C (84F).
Black Corals
Don’t let the name fool you, when live coral polyps are covering the dark skeleton for which they are named, Black coral (Antipathidae) bushes are anything but black. Reaching up to 1.8 meters in height these bushy yet finely branched, tree-like corals are stunning. The live polyps come in a range of colors including white, tan, green, rust, and orange and determine the color of the bush. Maybe it’s the sulfur and the rich nutrients provided by the volcanic black sand or the contrast to the black sand itself, but at Hot Rocks black coral bushes are more vibrant than in other places with an almost neon glow.
Because of their unusual luster and lightweight nature, black corals are highly valued and have been used for centuries in jewelry making and as medicine. An aquarium trade in live specimens has also been reported. Harvesting is mainly carried out by hand but also by submersible and net dredging. Black corals are slow to recover from harvesting and are currently considered globally threatened. Find the story of coral here, and help protect these beautiful corals by refusing to buy black (or any other) coral jewelry.
For divers, Black coral bushes not only create a visually stimulating dive site they also offer an excellent environment for critters to make a home in. Take a little time to really look at the bush and you’ll be surprised by what you may find. Often hovering in and around the bushes are Ornate Ghost pipefish and Golden Sweeper fish. Long-nosed hawkfish are commonly seen inside the bush flitting from branch to branch. Look a little closer and focus on the branches themselves and you may find a whole “colony” of critters, including Tozeuma shrimp (Tozeuma Armatum), Xeno crabs (Xenocarcinus conicus) and nudibrachs.
Volcanic Black Sand
Just like a treasure hunt, black sand (or muck diving) is one of the best places for marine life enthusiasts, looking for odd critters. Muck diving is even offered as a PADI specialty, these days.
Some of the craziest critters make their home hiding in the black sand, and detritus that usually collects in small depressions around the dive site. While diving Hot Rocks your dive guide will be looking for Spiny devilfish (Inimicus didactylus), Cockatoo waspfish (ablabys taenianotus), long arm octopus and Solar Powered nudibranchs (phyllodesmium longicirrum). Often times these camouflaged critters can be found hiding in plain sight.
Whether it’s the nutrient rich sand with sulfur deposits that the critters feel at home in or by providing a dark background for the bright corals and the colorful invertebrates, Colors Pop at Hot Rocks. The site has so much to offer! The hardest decision an underwater photographer has to make when diving the site is which lens to choose.
“Wide Angle or Macro?”
This is a common question when we pull into Sangeang. The dives around this volcanic island are so diverse it’s hard to commit. As mentioned before, many dive sites offer both vibrant reef and an abundance of macro subjects. Granted, you won’t usually see pelagic fish here, but the reefs on some of the sites are so unique it can be awe-inspiring. Guests are often blown away by the diversity and vivid colors of the reef and critters. While the number of critters guides are likely to show can keep you busy an entire dive shooting macro, underwater photographers often feel inspired to capture wide angle images as well. After the dive, we would frequently hear “can we dive here again, I’d like to change my lens.” Because of that Adelaar Liveaboard Cruises usually offers the option of diving here twice
Hot Rocks isn’t the only dive site at Sangeang. Some of the notable sites include:
The Lighthouse and Tikno, which also offer a mix of reef and black sand. Bontoh Village on the west side and Menjengan Wall on the south round out the list of the usually dove sites at Sangeang. From frogfish to ghost pipefish to a whole host of Nudibranchs and beyond; on any given day any of these sites can serve up a wide range of critters that will result in a dive you will never forget.
