November 30, 2007: Increasing Russian air and naval activity off Norway's north coast (in the Bering Sea) has prompted Norway to send some of its Ula Class submarines [PHOTO] north to investigate. The Russian ships, which stayed out Norwegian territorial waters (just barely) proceeded to use their sonar on the Norwegian subs. It's unclear if the Russians were able to find the Norwegian boats often, because these subs are acknowledged by other NATO navies as the most difficult to find when submerged.

The six Ula Class subs were built in Germany between 1987-92. They displace 1050 tons and are 194 feet long. With a crew of 21, they have eight torpedo tubes and 14 torpedoes. Surface speed is about 20 kilometers an hour, submerged speed is 42 kilometers an hour. They can stay at sea for about three weeks at a time. Their small size makes them particularly hard to detect submerged, and the Russians may be finding that out, or not. The Ulas are being upgraded with new electronics and sensors, which makes them better able to sneak around and just listen to the Russian ships above. Ulas can stay under water for about two days, if they don't move around much. Whatever the Ulas do discover, probably won't be made public, and only shared with some NATO allies. The Ulas are expected to remain in service until 2020.