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.

[4] More recently, after transfer to the US, Pisces IV was certified for use by the American Bureau of Shipping in 2000, and underwent modernization and upgrading in 2001 in preparation for the diving season.

Associate director of the Hawaii Undersea Research Laboratory, John Wiltshire, said the discovery was "probably the most significant archaeological find in the Pacific".

Analysis of the wreck shows that it was brought down by a shell from the USS Ward that breached the sub's conning tower, confirming that the United States fired the first shot in its war with Japan.

The manipulator arms are also used to place temperature probes in hydrothermal vents, and occasionally for movement instead of thrusters, in order to avoid disturbing sediment.