From The Depths is a complicated game with lots of little things that aren't explained well, or sometimes even at all. Hopefully this guide will help you get just a little bit better.
Tips and Tricks: Things the Game Doesn't Tell You
Anti-torpedo torpedoes, how do they work?
Torpedoes, the bane of any ships existence, how exactly does one defend against them? Anti-munition warners don't work underwater, so there is no way to launch interceptors. Or is there? There is!
If one were to look in the detection components section of the build menu, and then peer closely at the description of the Passive Sonar, they will come upon a miraculous discovery! The Passive Sonar can detect the sonar from torpedoes. What this means is that if you have a Passive Sonar hooked into your detection, it will pick up incoming torpedoes, which allows you to use an Automated Control Block to fire your torpedo interceptors. No more pesky torpedoes coming to wreck your day!
Detection Systems, How Do?
Something I recently learned by accident regarding detection systems, is that you don't necessarily need a wide variety of detection methods. In fact, you can achieve fairly good accuracy using only Coincidence Rangefinders.
The AI will pool the results from all the detection methods available, and average out the errors to arrive at a very close mark. I think. Maybe. Don't quote me on this.
Maximum Armor - Crysis: How to Maximize Armor in a Smaller Space
Do your ships always turn into unwieldy bricks? Do you find your self having to slap on THICC slabs of armor, only to have the enemy still penetrate you with their pesky HEAT and HESH shells? If so, you might find this next trick useful. One of the best ways to protect against those shell types is with an air-gap in your armor, but that gap takes up space and reduces your AC. However, placing a slope block will count as an air-gap, triggering the shell early, while also acting as a spall shield within the space of one block.
How To Not Capsize Your Ship
You've just completed your newest ship. It's awesome, it's amazing, it's... rolling over and sinking to the bottom of the ocean because you put too much weight on it. The bane of many builder's existences, how do you correct for rolling, pitching, and recoil? Maybe you are bad at weight management and it is simply too heavy. Maybe you crammed it so full of stuff that there isn't room for air pumps to provide buoyancy. Never fear! I'm going to introduce you to your new best friend, the PID block. I know, I know, it looks super complicated. HOWEVER! It is in-fact very simple to set up a system to keep any ship rock-steady in even the roughest of sea-states!
First what you need to do is place propellers along the bottom of your ship. Not many, you can get away with just 4, but more is better for redundancy. Now, you need to got to each of those propeller and press Q on them. This will open the propulsion editor so that we can make a few necessary changes. By default, all these propellers will be set to pitching. You need to right click on roll and pusher so that all 3 are green. Then, go to the control section of the build menu and get the PID (General Purpose). (You can use the AI version of the PID for this, but that way turns off if you turn off the AI. I prefer the general purpose because it is always on.)
You need to place down 3 of the PID's somewhere nice and protected, and then we can set up the system. Press Q on the PID. You will be presented with a lot of stuff, but you can safely ignore almost all of it. What we are focusing on is the inputs and outputs. You will need to set it to Roll, Pitch, and Altitude above mean sea level, spread across the 3 PID's. Then for outputs, you need to select propulsion Pitch, propulsion Roll, and propulsion Vertical, mapped to PID's with the respective inputs.
If you did all that correctly, your ship should now be floating almost as steady as a fortress. If your vessel is small, you might find it being thrown around a bit after setting this up. In that case, you need to lower the thrust of the bottom propellers. If your ship is sitting low in the water, that is also easily fixable using the Altitude PID that you set up previously. You will need to go back into the PID menu and look below type selection, where there will be an option to enable a fake set point. Once you have done that, simply input an altitude you want it to sit at, and adjust as needed. Bam, you now have a super stable ship that will (almost) never capsize.
Engines and Overheating
Now, I don't necessarily consider this one on the same level as the others I've talked about. There's a good possibility I was just too dumb to realize this until recently.
Are your engines too hot to handle? Are you constantly finding yourself running out of power in the middle of a battle because all your cylinder's overheated? Tired of weakening your armor belt because you had to snake some exhaust pipes through it? I have the solution for you!
I present to you... *Drumroll*
The Radiator block.
Don't give me that look, I can see you looking at me like I'm stupid. The radiator block can be your cool new friend. Radiators, assuming you have enough of them, completely remove the need for exhaust pipes to cool your engines. It isn't realistic at all, but it works. You can quite easily cool your engine to the point where it won't overheat even under max power draw, and also allows you to maximize your engine space as you don't have to leave space for connecting the pipes.
Always Read the Manual
Always, always, ALWAYS, read the descriptions of the blocks and do the tutorials. Recoil absorbers for APS? I just found out the other day you can attach them to Connectors. Blew my mind. There's just little things that if you don't read carefully you end up missing and making things harder for yourself.