This is the easiest way to get the little fishies in Subnautica for Food or Water!
Fabricate your GravTrap
First, you need a GravTrap (Gravity Trap). You can find fragments for it near the Grassy Plateaus along the way to the Aurora. You need a Scanner to scan the fragments.
You can then craft the Gravtrap using a:
- Copper Ore
Farm the Fishies
Once you have fabricated your GravTrap, enter the safe shallows and look for an area with alot of fish then throw your GravTrap. Or you can throw it anywhere - your choice. When you throw it, the GravTrap with pull the fishes as well as some outcrops too! You can pick the fishes up and bring em back to your lifepod.
Now you have your fishes, all you can do is dig in or get some water down the hatch!