For me it's the crator's edge crag zone side. Along with a steep drop off, it's also very dark and the sound of many bonesharks all around you do their off-putting scream now and again. I had a go of building a base there but when trying to place lights and it lit up the dark waters and I could clearly see how many bonesharks swam in the one section, I packed up and relocated. Second would be the crator's edge followed by the crash zone.