For the first time the depth of the Baikal was measured probably by the first people catching the fish there. First bathymetrical investigations of Lake Baikal were held by the scientist B. Dybovsky and V.Godlevsky that were researching the bottom–dwelling organisms along with the bottom terrain. The deepest depths are located next to the eastern shore of the Olkhon Island, between Izhemey and Khara-Khushun Capes, at 8-12 km east form the shore. The investigations held in 1960 by heaving the lead revealed the Baikal’s depth of 1620 m. The data given by the depth sounding had been precised with account on the sound speed in water, and the depth resulted in being equal to 1637 m. That figures were indicated on the new bathymetrical map published in 1974.

Within the expeditions organized to the Baikal in 2008, the submergences of the under-water vehicles “Mir” had been carried on. The crafts “Mir-1” and “Mir-2” landed the Baikal’s bottom at the depth of 1580 m. It is a new world submerging record among the hydrospace vehicles operating in the fresh water.

The overall number of the submergences planned within the “Mir” investigating mission that began on July 29, 2008, attains 160 ones.  The research’s purposes comprise the Baikal’s bottom investigation, its tectonic and geological properties, as well. Besides, the scientist from the various research institutions are planning to investigate thoroughly the ecosystem of the Lake along with the hydrocarbon deposits within the bottom.

The Baikal’s bottom possesses strikingly expressed dissected bottom terrain. The waterside shoals and underwater slopes are presented along the all the coast to various extent. There is observed clearly three main lake craters as well as under-water ranges. The most perfectly seen Academichesky Range spread from the Olkhon Island up to the Ushkany Archipelago. Its mileage approximates to 100 km, the maximum height over the Baikal’s bottom is 1848 m. If the fact that the thickness of the bottom deposits in the Baikal attains 6,000 m is trustworthy, it can be supposed that ones of the highest mountains (7000m) in the world are submerged by the Baikal.