How do you display co-ordinates?
Hit "F1" on top of your keyboard.
It will open a semi-transparent pane showing tons of useless stuff.
Just above 1/2 way down, it will say "Camera World Pos", which show coordinates.
It also names the biome you are in.
The coordinates are expressed as "X,Y,Z", which sucks.
Find a map for this game on Google, and realize all coordinates can have a + or -.
220, 170, -1430 is NOT the same as 220, 170, 1430.
Think of your computer monitor when you look at a map: 1920x1080 is lengh across, then height.
All maps are read assuming you are looking North.
The map for Subnautica goes fom zero (0) to about 2000 in every direction.
+2000, -2000 North and South and
+2000 to -2000 East and West.
The middle # is the depth.