This July Russia will start training the future crew of the second Kilo-class submarine Vietnam has agreed to buy from the country, Russian news agency Interfax reported Monday.
The submarine named "Ho Chi Minh City" set off for sea trials April 28, four months after being launched.
Interfax reported that the submarine embarked Monday for a two-week sea trial.
It will arrive at the seaport town of Baltiysk early next month and return to Admiralteiskie Verfi shipyard in St. Petersburg by mid-June.
In July, the training will get underway for Vietnamese crew, according to Interfax.
It is expected that the submarine will be delivered to Vietnam in late October.
During the visit of Vietnamese Prime Minister Nguyen Tan Dung to Moscow in December 2009, Vietnam signed a US$2 billion deal to buy six diesel-electric submarines from Russia.
Russia has promised to deliver them all by 2016.
In another Russia visit on May 13, Dung called on the factory "Ship Repair-West" in the Russian seaport city of Kaliningrad and watched the first submarine built for the Vietnam Navy undergoing sea trials.
The submarine named "Hanoi" has undergone 23 successful dives.
The Voice of Russia reported that the third submarine, named "Hai Phong," will be launched this August.
Kilo-class submarines, nicknamed "Black Holes" for their ability to avoid detection, are considered to be among the quietest diesel-electric submarines in the world.
They are designed for general reconnaissance and patrol missions, as well as anti-submarine and anti-ship warfare.
They have a displacement capacity of 2,300 tons, a maximum depth of 350 meters, and are equipped with six 533-mm torpedo tubes with a firing range of 9,600 km.