In 2018-2019 the deepest points of each ocean were mapped using a full‐ocean depth Kongsberg EM 124 multibeam echosounder abord DSSV Pressure Drop. In 2021 a data paper was published by Cassandra Bongiovanni, Heather A. Stewart and Alan J. Jamieson regarding the gathered data donated to GEBCO. The deepest depth recorded in the 2019 Challenger Deep sonar mapping was 10,924 m (35,840 ft) ±15 m (49 ft) at 11°22′08″N 142°35′13″E﻿ / ﻿11.369°N 142.587°E﻿ / 11.369; 142.587 in the eastern basin.