“The Petropavlovsk-Kamchatsky launched a cruise missile of the Kalibr complex at a ground target from a submerged position in the Sea of Japan. At the estimated time, the missile hit the coastal target position on the tactical field of Surkum [in the Khabarovsk region]. The firing range exceeded 1,000 kilometres,” the Russian Navy’s Pacific Fleet said in a statement. Russia’s Pacific Fleet said the exercise also included covert movement and support from navy vessels, aircraft, and drones.

Japan continues to assert territorial rights to the Kurile Islands in the nearby Sea of Okhotsk. Japan calls the islands the Northern Territories. Soviet troops seized them from Japan at the end of World War II.

The dispute has kept Russia and Japan from signing a peace treaty formally ending the war.

According to TASS, project 636.3 submarines (NATO reporting name: Improved Kilo-II) belong to the third generation of large diesel-electric subs and are among the world’s quietest underwater cruisers.

The ships are powered by two diesel generators and an electric drive, giving them enough power to make ten knots at the surface and seventeen knots underwater.

Kilo-class submarines normally dive to just 787 feet, with a maximum diving depth of 984 feet. The submarines do particularly well in shallow water, operating closer to the seafloor.

Kilos’ hull is reportedly shaped like a drop of water, helping it reduce water resistance. The propulsion plant is isolated on a rubber base so it doesn’t touch the hull, preventing vibrations from turning into noise that can be heard outside the boat.

The ship has a rubbery anechoic coating to deaden noise emanating from the submarine. The air regeneration system can keep the crew supplied with oxygen for up to 260 hours, giving the ship almost two weeks’ worth of underwater endurance.

The Kalibr is a Russian surface ship-, submarine-launched and airborne anti-ship and coastal anti-ship (AShM), land-attack cruise missile (LACM) and anti-submarine missile. It has many configurations according to the mission and it is developed by the Novator Design Bureau. They have subsonic and supersonic versions while subsonic missile’s range is accordingly greater than those of the supersonic versions.