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Four-season navigational buoys

Learn about our buoys in the St. Lawrence River, the advantages of four-season buoys and the different models.

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Buoys in the St. Lawrence River

The Canadian Coast Guard is deploying 184 four-season lighted navigational buoys in the St. Lawrence River shipping channel between Quebec and Montreal. This follows a contract awarded in late 2018. These buoys are designed to withstand the severe ice and tidal conditions found in the St. Lawrence. The installation of the buoys began in early 2019 and will continue into 2020.

Four-season buoys help to improve navigational efficiency and safety to mariners.

Advantages of four-season over seasonal buoys

We’re replacing our seasonal navigation buoys in the St. Lawrence River between Quebec and Montréal with these new four-season buoys.

Seasonal navigational buoys only provide 6 to 8 months of lighted navigation. They need to be deployed every spring and switched out every fall. Once out of the water, they must be inspected and repaired.

The new four-season buoys allow us to operate more efficiently. They can withstand very severe ice conditions. The ice flows around the buoy or, in the worst conditions, tilt the buoy and flow over it. When the ice recedes, the buoy returns to its upright position.

Four-season buoys remain in the water year-round, providing increased lighting, dependent on ice conditions. In addition, they only require service and maintenance every 2 to 4 years.

Buoy models

We developed 2 different four-season buoy model sizes to deploy in the St. Lawrence shipping channel. These 2 model sizes are the 1.3 metre and the 0.7 metre, each best for different water depth conditions.

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A 1.3 metre model buoy

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A 0.7 metre model buoy

Dimensions and specifications

Dimensions and specifications 1.3 metre model 0.7 metre model
Length 9.5 metres 8.7 metres
Mass 4,000 kilograms 2,100 kilograms
Hull diameter 1.3 metres 0.7 metres
Air draft 2.5 metres 2.0 metres
Tilt angle Less than 6 degrees at 5 knots Less than 6 degrees at 2.5 knots
Water depth 9 to 30 metres 9 to 25 metres



Canadian Coast Guard introduces a new four-season buoy system that will enhance navigational safety, remaining in the water year-round and providing increased lighted navigational aids to mariners, ensuring the safe transport of people and goods on our waterways. The four-season buoy project is a homegrown solution that we conceived and developed.

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