Why can’t i build anything in deep water when I have build anywhere on?
What game are you having issues with?
I’m assuming you’re referring to Sons of the Forest?
To build on water you need to have foundations on the bottom of the lake. The trouble is that you cannot carry logs underwater, which is a game limitation the trainer can do nothing about.
To build on water, you need to wait until Winter (or create a custom game with your starting season as Winter). Then build your base on top of the ice of the frozen lake. When the snow melts in Spring the game will automatically place foundations underneath the base where it’s normally impossible/too deep for you to build.
(Beware that there is always a chance the developers will remove this “feature” in a future update, and hence your base may collapse into the water if they do).
There are hundreds of tutorials online that teach you how to build on a lake.
Note there is one lake in the game that does not freeze in Winter because the water entering it from a nearby river is flowing too quickly for it to naturally freeze.
If this isn’t about Sons of the Forest, make sure to be more specific and let us know what game you’re referring to.