С-178 (S-178) was a Project 613B (NATO: ) diesel submarine of the Soviet Navy. On October 21, 1981, in the Sea of Japan, the submarine under the command of Valery Marango was hit by a cargo ship. The collision killed 32 sailors. Collision and loss On 21 October 1981, S-178, under the command of Captain Third Rank V.A. Marango, was transiting on the surface at , returning to base after two days of sound trials. The sea state was 2 (less than one-metre waves) and night time visibility was unlimited. The starboard diesel was under repair, so the propulsion plant was aligned port diesel, starboard electric motor. For convenience, the diesel mechanics and electricians had opened the watertight doors between compartments. In addition, the cooks had opened other watertight doors so that they could serve dinner. At 19:30 local time, S-178 received permission to save time by entering Golden Horn Bay, in downtown Vladivostok, through a combat training range. The port officer who granted that permission had just assumed the watch, and was unaware that the off-going watch officer had granted similar permission to the refrigerated stores vessel RFS Refrizherator-13 to leave Golden Horn Bay through the combat training range. Watchmen on RFS-13 noticed navigation lights which they took to be a fishing trawler. At about the same time, the pilot of RFS-13 noted a contact on radar which was showing decreasing range and zero bearing rate, indicating a collision course. On S-178, sonar reported detection of another vessel, but that report was lost in the relaxed atmosphere prevailing on the submarine after dinner. Nautical "rules of the road" and the rules of navigation in Vladivostok port agree that the ship should yield the right-of-way to the submarine; however, master V.F. Kurdyukov of RFS-13 chose not to alter course. The lookouts on S-178 did not spot RFS-13'''s running lights against the background of the lights of Vladivostok until the ship was upon them. The captain gave the orders "hard right rudder" and "Signalman, illuminate that vessel", but too late to have any effect. At 19:45 Refrizherator-13 struck S-178 at an angle of 20–30 degrees on the port side of the sixth compartment at a speed of , tearing a hole about two square metres in area. The sixth compartment flooded completely in 15 to 20 seconds. The boat rolled sharply, throwing the 11 men on the bridge into the water.