Heavy fog is extremely dangerous for any ship, and especially for a convoy of ships steaming close together. With little visibilty crews have almost no time to react to possible collisions, and it can be very difficult to determine what's the best way to avoid getting rammed. Using your Adlis lamps to signal isn't effective. In heavy fog the other ship might never see your signal. They will hear your horn, but by then it is too late!

Ordering engineering to stop all engines and dropping the anchor chains will slow you down, but it could also make you too slow to avoid a collision. In most cases, slowing down merely delays the collision, not preventing it.

Making an emergency turn to Port while giving full power to the starboard propeller and reversing the port one is exactly the wrong order to make. This combination of orders turns your ship's side right into the path of the merchantman.