This guide will let you know how to reach the Crag Fields in Subnautica.
Starting from the coral tube sticking up out of the water, you will need to head about 1-2 bumps to the right of the south, and you will end up at/in the crag fields.
If you want to explore the crag fields, it is recommended to bring a sea moth with an Mk1 Depth Module and perimeter defence, a high capacity 02 Tank, a sea glide, and a beacon can mark the biome to come back to it easier.
The main threat you will encounter is the bone shark; you can either avoid them or use perimeter defence against them. You can also kill them using your knife.
The coordinates for the location are (-195.6, -135.7, -869.8).