牛尾海
While The Hydrographic Office's 1943 publication did not have the definition of Outer Port Shelter, H.K.'s Agriculture, Fisheries and Conservation Department had deployed artificial reef to the Outer Port Shelter in the 2000s. They defined the area by coordinates instead. Roughly, it is a triangular area between Steep Island, Basalt Island and the southern shore of Jin Island (known as Tiu Chung Chau in the publication).