Seamoth sonar and defense upgrades - how do they work?

[Varinger]

As in title, I'm having some trouble getting these two to work (or give any indication that something has changed).

I've crafted them and loaded them into the upgrade slots. Out of the four I've loaded in, only the storage upgrade and solar power generator show any signs of functioning. Haven't had a chance to test the pressure upgrade. I have sonar, perimeter defense, solar power generation and storage loaded, but see the sonar and perimeter defense icons greyed out when I'm in the seamoth. The storage and solar power show up as green. Is there more that I'm neglecting to do in order to activate these things?

I read topics where someone mentioned charging the PDS vs just emitting a shock, which implies to me I need to manually activate it when I want to use it, but neither mouse button, nor any of the obvious keys seem to do the job. I've enraged a stalker and had it charge me to no effect, tried aiming at it and holding the mouse buttons down, one by one, and letting go, but nothing.

As for sonar, I'm lost as to what could be up with that.

Could it be related to the fact I'm on the stable version? Or that I'm in Freedom mode?

[Tenzek]

You have to select the sonar, then click to use it. Buttons 1-4 correspond to the upgrade slots.

[Varinger]

You're my new best friend. Thanks!

[Repairman Jared]

Originally posted by Varinger:

You're my new best friend. Thanks!

Holy crap he is my new best friend as well they really should put a how to use it er I suppose if I go in blueprints maybe it does.