The O-Class Submarine was a series of British submarines built during the early 1940s, primarily for use in World War II. These submarines were designed for anti-submarine warfare and had a displacement of around 1,000 tons when submerged. They were equipped with torpedoes and had the capability to operate at depths of up to 300 feet. The O-Class featured a streamlined hull for improved underwater performance and was powered by diesel engines for surface travel. A total of 12 submarines were constructed, and they played a significant role in the Royal Navy's efforts against enemy submarines and surface vessels during the conflict.