I think weapons or defense Mechanisms wouldnt be such a good idea. The feeling of Subnautica is based of you feeling helpless and having to swim away from terrifying sea monsters.
What about an power storage module for the base?
It could be build like a window (2 Energy Cells, 2 copper wires and 1 Titanium to store 200/300 power units.)
And we would need an explanation why there are no weapons in the workers pda b…