Sonar Station — Legacy: Into the Depths

Drifter says he's put the salvage you've brought him to good use, but that he needs parts from a different type of machinery to further improve his device.

"I need Savathûn's swamp to wash up a few finishing touches for my rig," he elaborates.

He instructs you to travel to Savathûn's throne world and secure pieces of Pyramid technology from the Scorn. With it, he can modify his extraction equipment to work in the deepest trenches of Kraken Mare.