Paltus-class submarine
The "Paltus" class submarine is a Russian special purpose mini-submarine of project 1851.1. Two boats were completed - "AS-21" and "AS-35" as a follow up of the single "X-Ray" class boat "AS-23" (Project 1851). They are both part of the 29th special submarine squadron at Olenya Guba. The surface displacement is approximately 300 tons with a length of . The propulsion comes from nuclear power with the operating depth in excess of . The designer, according to Polmar was Sergei Bavilin who had designed the earlier diesel electric Project 865/Piranya small submarine of similar dimensions. Paltus-class