The team includes members of previous expeditions to the Titanic and the USS Monitor. They will test for pollution in the lake, one of the purest sources of water on the planet. They will also look for new species of fish and lake life, and explore shipwrecks.

On August 7 at 7:30 pm at the Bookworm bookshop and restaurant in Beijing Schwankert will explain the goals of the expedition and show photos of the lake and its environs.

Danwei recently asked Schwankert a few questions about the expedition and the lake.

Danwei: Where is this lake and why does it contain so much of the world's fresh water?
Schwankert: The lake is in northern central Mongolia (the country, not the Chinese autonomous region), not far from the Russian border.

There are actually very few large sources of freshwater on the planet. Lake Khovsgol is an ancient lake, two to five million years old, and was formed through a combination of geologic movement and glacier action. Its size — 136 km long, 30 km wide in some places, and 262m deep — makes it one very large drink of water.

Danwei: Are you sure it's the first time anyone has dived in it?
Schwankert: We're not claiming it's the first time anyone has dived in the lake. One of our team members dived there in June. However, it has only been dived a few times, and we are the first diving scientific expedition to the lake. No one will ever have spent as much time below its surface as we will.

Danwei:: What types of fish will you see in the lake? Whose ships are lying at the bottom of the lake? Are there skeletons of rejected Mongolian concubines?
Schwankert: There are nine types of fish in the lake, including Siberian greyling. Fish in the lake tend to be very big. They are consumed by local people but not enough to endanger the population. Lake Khovsgol is a Mongolian national park, so commercial fishing is not permitted.

There are two ships that we know of at the bottom of the lake. One is the Mongolian Navy ship, the Sukhbataar. The other seems to be a cargo ship, and was dived for the first time by one of our team members in June. We'll be going to both for a closer look.

No former concubine skeletons on the bottom, but there may be Buddhist relics thrown into the lake in the 1930s by monks who wanted to preserve them during a persecution. However, it's not a treasure hunt; anything we find will be returned to its rightful owners.

Danwei: What does Khovsgol mean?
Schwankert: Ocean.

Danwei How will you test for pollution? If the lake is polluted, where is that pollution likely to have come from?
Schwankert: We're receiving support from scientists who have done work at Khovsgol before. We will use equipment they provide, and may even just take samples to ship back to them for their own analysis.

Where pollution would come from is the big question. It could potentially drift in from Russia or maybe China, or elsewhere in Mongolia. It could also be from within the lake itself, due to pre-national park dumping, or perhaps from the shipwrecks or the 30-40 cars that lie on the bottom, having crashed through the ice when the lake's surface is used as a road in the winter. We have a sonar unit traveling with us, so we may be able to discover other wrecks or dump sites that were previously unknown.