The story
From the Hawaiʻi Mapping Research Group, which performed a sonar survey of the region in 1997, and discovered the deep.
Etymology from Wiktionary, CC BY-SA 4.0.
HMRG Deep
Today it means: Former name of Sirena Deep: a deep in Mariana Trench, Pacific; second deepest place in the Mariana Trench, and third deepest place on Earth. Full definition →