Nice idea.

Recovering bodies could be implemented easily, and it makes sense. "The family of the captain has requested his body be retrieved from the ship, offering a hefty reward"

Would you be interested in a mod that allowed you to dock with any derelict that has a "wrecked docking port"? There are wrecks that have a regular docking port, and it is possible to dock with those, I don't know if you noticed that. The green docking port bar doesn't appear, but when the ports are...

The sonar effect could be anything from a visual only "disorienting" effect, or it could possibly stun the diver for a moment. It could be argued that the heavy deep diving suit protects the wearer from the extreme damages that could kill them. The sonar should definitely be audible for divers, thou...