There are several good reefs off the coast of the eastern side of Kalimantan.
Out in the Makassar strait lie a number of sites are famous for the large gatherings of manta rays and breeding grounds of turtles. There is also a unique biological wonderland in the form of a brackish inland lake at Kakaban. All the islands are relatively close together so can be visited in the same trip.
Visibility is often lower here than other parts of Indonesia due to silt from the river in Tanjung Redeb. Samama or Derawan usually have the lowest visibility, Sangalaki a bit better because it is a little further offshore, and Kakaban and Maratua even better because they are even further out.
Kalimantan at a glance
Accommodation : Resort/Bungalow
Highlights : Mantas, jellyfish lake.
Average cost of a dive : $30
Dive Sites : 20+
Dive Operators : 3+
Getting there : Boat from mainland, 60 -120 minutes.
Rainy Season : November to March.
The map below is interactive so click on the dive site to get more details.