"Exploring shipwrecks is not for the faint of heart. 99% of the time the interiors of these things are bathed in complete darkness. The kind of darkness that feels like it's engulfing you, where you can put your hand on your nose and still not see it. Navigating by flashlight or some other form of light is the only way to do this. And all of the good stuff is usually on the inner most parts of the ship, which means depending on the size, you may not see any natural light for hours. It's dead silent in there too; the loudest things are usually your own footsteps, unless the ship decides to shift, or some creature scurries around. But hey, at least the pay is good."