what is the deepest trench in the Indian Ocean

That would be the Java Trench, also known as the Sunda Trench. It's honestly a pretty wild spot when you think about how deep it actually goes, stretching down to about 7,200 meters or so. Navigating through those waters in the region always gives me a bit of respect for how much is hidden down there under the surface.

I've crossed parts of that area a few times during my shifts, and even though you're just looking at the horizon, it's crazy to imagine the sheer drop-off below the keel. Most people just think of the ocean as one big blue expanse, but that trench is definitely the undisputed king of depth in the Indian Ocean.