First launched in 1991, the SHINKAI 6500 is a manned submersible that can dive to depths of 6,500 meters (20,000 feet). Operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Shinkai has completed over 1300 deep dives in the Pacific, Indian and Atlantic oceans, as well as the Sea of Japan.
In 2012, the vessel underwent a major upgrade, including conversion from a single aft prop to two thrusters and the addition of one more horizontal thruster for maneuverability. Hasegawa offers the kit with two build options to reflect the original and upgraded version of the submersible. To clarify the build process and the differences, the instruction sheet includes complete build sequences for each version. It's worth taking the time to go through the instructions – particularly since other sub-options are offered within each build – to end up with the configuration you've chosen.