There's a crate in the water you should be able to see from the surface, and reach when you have the rebreather that contains the Lightsaber Emitter Valor and Wisdom. If you continue past the crate you’ll reach the lower level of the Abandoned Workshop.
If you have Force push you can also turn left to find a bridge you can push over to find a Scomp crate that requires a BD-1 Scomp link upgrade to open with a BD-1 Z’Gag wave skin inside.
(Image credit: EA) Star Wars Jedi Fallen Order walkthrough - Subterranean Refuge
