WWe were just a few hours out oof London, in the notorious Dover Straits on my fififirst trip to sea aat the age of 16, when we collided with another ship in thick fog. It was only a glancing blow so we were able to carry on with our voyage, but it was a lesson about the dangers of fog. At sea, thinthings can happen unexpectedly, and you realize just how your woworld changes when visibility drops to zero.
That was before the days of electronics. We had no radar, no GPS, and no AIS, so it was a bit like navigating with a stick and we had to rely on listening and locating fog signals. Modern electronics have made a huge difference to navigating in these conditions. They give you confidence to keep going when you can’t see ahead, and you tend to rely on them totally, which is where the danger lies. GPS positioning on the chart plotter can give you a lot of confidence that you know where you are, but radar and AIS have their limitations when it comes to collision avoidance in fog, and cannot be trusted implicitly to detect everything that is around you.
TRUST YOUR SENSES
With two displays in the pilothouse—one showing the radar and one the electronic chart—you are likely to be focussing on these screens rather than looking out of the windows. In theory, these two displays show you everything you need to know, so why bother with keeping a visual lookout? The problem is that you cannot be sure that the radar will show everything that is moving on the water, particularly if there is a sea running. That is when the radar will pick up the returns from the waves as well as those from small boats and the small-boat returns can get lost in the sea clutter.
So the visual lookout is vital in fog, not only to reassure yourself that you will see other boats that may be close but also it is a legal requirement under the Colregs. Rule 5 states, “Every vessel shall at all times maintain a proper lookout by sight and hearing as well as all available means.” Hearing implies that you should be listening for fog signals as well. I can’t remember the last time I heard any ship making fog signals and this requirement seems to be studiously ignored these days in fog, because ships and boats rely on their radar alone.
In fog, you need all hands on deck, and the lookout should be outside on the flybridge or deck. There, the lookout will not be distracted by the electronic displays and will have a much clearer view. It can be a real struggle to keep the concentration necessary for a lookout, so you need to change the watch at short intervals. It is best to have one person on visual lookout and one on the radar so that full concentration can be given to both.
Operating the boat on autopilot in the fog has advantages. First, it removes the need to have someone steering
the boat so they can concentrate on the lookout. Second, it will stabilize the radar pictures and make them much easier to interpret. However, make sure you know where the autopilot disconnect button is so you can quickly take over manual control. If you have MARPA on the radar to show the heading vectors of other vessels, then having the picture stabilized will make these easier to see. within the visibility range, but adjust for the visibility range with oncoming vessels.
You are required to proceed at a safe speed having regard to the state of the visibility.
Your speed should also be determined by the characteristics, efficiency, and limitations of the radar equipment, and the possibility that small vessels may not be detected at an adequate range.