''Pisces IV'' is a three-person, battery-powered deep-submergence vehicle (or DSV), with a maximum operating depth of . The craft was built by Hyco International Hydrodynamics in Vancouver, and is currently owned by the Hawaii Undersea Research Laboratory arm of the

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with Weather forecasting, forecasting weather, monitoring oceanic and atmospheric conditions, Hydrography, charting the seas, ...

. It and its sister, '' Pisces V'', are Pisces class submersibles used by the NOAA for oceanic exploration. ''Pisces IV'' was constructed in 1973 and immediately placed in the service of the Department of Fisheries and Oceans of Canada. The DSV was used by the Institute of Ocean Sciences and operated at different times in the Atlantic, Arctic, and Pacific oceans. After over 1886 dives, budget cuts forced the cancellation of support for the project. ''Pisces IV'' has since been replaced in that role by '' ROPOS''. More recently, after transfer to the US, ''Pisces IV'' was certified for use by the

American Bureau of Shipping The American Bureau of Shipping (ABS) is an American maritime classification society established in 1862. Its stated mission is to promote the security of life, property, and the natural environment, primarily through the development and verific ...

in 2000, and underwent modernization and upgrading in 2001 in preparation for the diving season. During training cruises in 2002, ''Pisces IV'' and its sister ''Pisces V'' found a Japanese midget submarine outside

Pearl Harbor Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the Reci ...

that had been detected on the morning of the attack on the harbor in 1941. Associate director of the Hawaii Undersea Research Laboratory, John Wiltshire, said the discovery was "probably the most significant archaeological find in the Pacific". At the time of its discovery, on 28 August 2002, the search for the sub had been ongoing for 61 years. Analysis of the wreck shows that it was brought down by a shell from the USS ''Ward'' that breached the sub's

conning tower A conning tower is a raised platform on a ship or submarine, often armoured, from which an officer in charge can conn (nautical), conn (conduct or control) the vessel, controlling movements of the ship by giving orders to those responsible for t ...

, confirming that the United States fired the first shot in its war with Japan. Today, ''Pisces IV'' and its sister ''Pisces V'' spend most of their time diving near Hawaii. Both are contained on the ''R/V Ka‘imikai-o-Kanaloa''. The subs are serviced between dives on the ship's deck, and are ready for launch on the next day, and one is generally kept on deck in ready status for the majority of any cruise. The majority of information gathered by the sub comes from its two cameras, one of which is generally on at all times. ''Pisces VI'' is equipped with a single "bright light" camera and low-power black and white camera, both of which can be controlled by scientists on board as seen fit. The low-power camera is used to record the activities of organisms that otherwise respond poorly to bright light. Another, higher-definition camera is also available. Samples are collected by a pair of manipulator arms; skilled pilots can use the sub's two arms, the right one more versatile than the left, to collect samples and store them in a mounted basket for later evaluation. The manipulator arms are also used to place temperature probes in

hydrothermal vent Hydrothermal vents are fissures on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hot ...

s, and occasionally for movement instead of thrusters, in order to avoid disturbing sediment.

References

{{DEFAULTSORT:Pisces 4 1973 ships Submarines of Canada Pisces-class deep submergence vehicles Ships built in North Vancouver Submarines of the United States