■Kairei's Mission 1)To operate the ROV Kaiko In March 1995, Kaiko succeeded in diving to the Challenger Deep (10,911 m) in the Mariana Trenches. Kairei will serve as the mother ship for the 10,000-m class ROV Kaiko and perform seafloor surveys in the seafloor valley. 2)To survey Deep Crustal Structures beneath the Sea The Kairei is equipped with a huge multi-channel reflection survey system, which emits a sound wave from a source called an airgun and receives signals reflected at the strata in the oceanic crust by streamer cables. By analyzing the data, seafloor crustal structures of 10 km or greater can be resolved and examined in detail. 3)To survey the Deep Sea Bottom The Kairei is equipped with a multi-narrow-beam echo sounder, capable of measuring depths up to 11,000 m. Using this echo sounder, the Kairei can create a wide-range topographic map of the seafloor in real-time. At the same time, using the sub-bottom profiler, she can also identify strata and faults at the surface of the deep seafloor. 4)Decreasing ship noise To create optimal conditions for use of these echo sounders, we have taken measures to reduce noise radiated by the ship.