I voted for 3d only. But I don't want to see some health bar or percentage over the equipment. I want to ask the crew. Some parts were considered unrepairable only after days of toiling. So unless an engine is completely blown up I don't want to see "unrepairable" after 5 seconds.
And I'm not sure why we can only repair one piece of equipment at one time. I'd like to have damage assesment when i talk to the crew, as dialogue choices, not as a diagram.
Kaleun: "Chief, damage report!"
Chief runs through the boat and comes back sweating: "Water leaking in the bow compartment, we have leaking batteries, there was a fire in the galley but we managed to put it out, and we have a dislodged torpedo in the aft section that fell on a noob. He's hurt, the medic's looking after him. Also the left electric engine isn't working".
Kaleun: "Contain the leak and fix the batteries asap. Take all the men you need. The engine can wait."
Kaleun walks to a sailor in the CR: "You, fix that bulb, it's flikering too much!"
Then he goes to the bow section and asks another sailor: "How's the progress?"
Sailor: "Almost done sir, 5 more minutes or so".
Kaleun goes back and asks another: "How's the wounded sailor?"
Sailor: "No idea sir"
Kaleun:"Then go there and bloody find out!!! After that go help with the engine repair."
The schematics of the sub could be use as a minigame to speed up repairs with the risk of busting the sub for good
.