I think that a lot has to do with the other elements in the scene…
When talking about a ship, what size are the waves and how deep can you see the ship in the water (if you can see 50 cm deep, then that is 50 cm of the ship, which is more than 300m large…(see also here: https://cgcookie.com/lesson/ocean-lake-demo).
The Camera Settings are more an artistic decision. (Although DOF might help a bit…)
