2025-12-30

Navigating in fog: How the port stays safe in limited visibility

A thick fog over the port is not uncommon in winter. Fog creates a charming backdrop, but also poses a significant risk to shipping. Limited visibility makes manoeuvring more complex, especially in an environment where hundreds of movements occur daily. How is safety maintained in such conditions?

Advanced technology on board

Ships are equipped with a range of sophisticated systems that help them navigate when visibility decreases. These technologies provide a crucial complement to the crew’s experience:

A foggy day in the harbour where we see thick fog around a ship and an open bridge.

Radar

Detects obstacles and other vessels, even when the surroundings are shrouded in fog.

AIS (Automatic Identification System)

Continuously transmits data such as the ship's name, position and speed. This allows ships to better judge each other’s position and movement.

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Adjusted cruising speed

In foggy conditions, ships often choose to slow down to minimise risks. 

Foghorn

Especially at sea, ships use foghorns to make their presence audible to other vessels. 

Vessel Traffic Services: keeping an eye on the water

Safety is also closely monitored on shore. Our colleagues at Vessel Traffic Services (VTS) continuously monitor shipping movements in the port using radar images and AIS data displayed on 65-inch screens. 

 

This allows them to inform ships in good time, avoid conflicts, and intervene quickly when dangerous situations arise. This makes VTS an important link in creating a safe and clear view of traffic in the port. 

When are ships kept at the quay?

At times, visibility is so poor that departing is no longer safe. There could be two reasons for this:

  • The captain does not consider the situation safe enough.
  • The law does not allow it. Clear restrictions apply in dense fog, especially for larger ships. 

Safety always comes first; in such conditions, postponing a voyage is the wisest choice. 

Tug boat on a foggy day next to a big ship while performing the tug task.

The role of the harbour pilot

In conditions of limited visibility, the expertise of the harbour pilot becomes particularly evident. Their knowledge of the fairway, currents, and local conditions is essential for guiding ships safely through the port. 

Antwerp

A pilot is required when visibility is less than 1,000 metres for movements in the non-tidal zones. 

Zeebrugge

Here, a pilot is required when visibility falls below 500 metres. On the breakwaters, light and fog signals support communication with captains, ensuring safety is maintained there as well.

How do we keep the port safe?

Would you like to learn more about how we keep the Port of Antwerp-Bruges safe and operational in all conditions? Find out more on our nautical services page. 

Find out here
Three people standing on a tanker in the fog.

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