A nuclear powered ballistic missile submarine.
It is used as a nuclear deterrence, designed for stealth, to avoid detection at all costs. Rascal uses many sound-reducing design features, such as anechoic tiles on her hull surfaces, carefully designed propulsion systems, and machinery mounted on vibration-damping mounts.
Its quipped with two UGM-133 Trident II, and Tomahawk missiles.
These ports are located behind the sail.