On the 9th of August 2014, two divers, Terence Lee and Leon Boey dived the volcanic crater lake of Batur.
At 1,031m above sea level and 18 square kilometers in size, this is a largely unexplored body of water.
After consulting a volcano expert, we learnt that the water level of the lake had risen a few metres in a couple of years, and the water quality has been deteriorating.
We wanted to find out if we could contribute to finding the causes of these problems, and if not, provide video documentation of the condition of the lake.
Here's what we found...