In 2002 "Kairei" revisited the Challenger Deep 16–25 October 2002, as cruise KR02-13 (a cooperative Japan-US-South Korea research program) with chief scientist Jun Hashimoto in charge; again with Kazuyoshi Hirata managing the ROV "Kaikō" team. On this survey, the size of each of the three basins was refined to 6–10 km long by about 2 km wide and in excess of deep. In marked contrast to the "Kairei" surveys of 1998 and 1999, the detailed survey in 2002 determined that the deepest point in the Challenger Deep is located in the eastern basin around , with a depth of ±, located about southeast of the deepest site determined by the survey vessel "Takuyo" in 1984. The 2002 surveys of both the western and eastern basins were tight, with especially meticulous cross-gridding of the eastern basin with ten parallel tracks N–S and E-W less than 250 meters apart. On the morning of 17 October, ROV "Kaikō" dive #272 began and recovered over 33 hours later, with the ROV working at the bottom of the western basin for 26 hours (vicinity of 11°20.148' N, 142°11.774 E at ). Five "Kaikō" dives followed on a daily basis into the same area to service benthic landers and other scientific equipment, with dive #277 recovered on 25 October. Traps brought up large numbers of amphipods (sea fleas), and cameras recorded holothurians (sea cucumbers), White polychaetes (bristle worms), tube worms, and other biological species. During its 1998, 1999 surveys, "Kairei" was equipped with a GPS satellite-based radionavigation system. The United States government lifted the GPS selective availability in 2000, so during its 2002 survey, "Kairei" had access to non-degraded GPS positional services and achieved single digit meter accuracy in geodetic positioning.