MOSCOW, August 5 (RIA Novosti) - The air supply on the deep-sea observation vessel (bathyscaphe) that has sunk in Biryuzovo Bay off the Kamchatka Peninsula will last for at least 72 hours, First Class Captain of the Russian Navy Igor Dygalo said Friday.

The accident is believed to have been caused by the vessel catching on a fishing net.

Seven people are on board.

A Russian Navy source said that food and water supplies in the vessel would last for five days.