According to the NBS Twitter feed, the first spotting happened in Latvia’s Exclusive Economic Zone (EEZ) waters about 27 nautical miles (50 kilometers) off the borderline, while the second sighting of the two vessels took place a bit farther off, about 55 kilometers away from the sea border.
Armed Forces on 16 MAR in LV EEZ 30 nmi from territ. waters spotted RU Navy's 2nd Kilo-class submarine, and hidrographic ship GS-403.
— NBS (@Latvijas_armija) March 16, 2015
The second tweet was posted in the evening, while the first of the tweets came out during the mid-afternoon.
Armed Forces on 16 MAR in LV EEZ 27 nmi from territ. waters spotted RU Navy's Kilo-class submarine.
— NBS (@Latvijas_armija) March 16, 2015