Pisces V is a type of manned submersible ocean exploration device, powered by battery, and capable of operating to depths of 2,000 metres (6,600 ft), a depth that is optimum for use in the sea waters around the Hawaiian Islands. It is used by scientists to explore the deep sea around the underwater banks in the main Hawaiian Islands, as well as the underwater features and seamounts in the Northwestern Hawaiian Islands, specifically around Kamaʻehuakanaloa Seamount (formerly Loihi).