A durable, foam-filled buoy platform for exposed marine sites

The HNF2.4 combines a Polyurethane Elastomer exterior, Stainless Steel Internal Frame and non-water-absorbing foam filling. Its large float, 4000 kg reserve buoyancy and site-matched mooring configuration support dependable navigation marking in channels, coastal waters and offshore locations.

Navigation buoys installed in exposed waters must remain clearly identifiable while responding to wind, current and mooring loads.

The HNF2.4 provides a large, high-buoyancy platform for the lantern, topmark and daymark structure. Its 4000 kg reserve buoyancy supports stable operation, while the mooring arrangement can be adjusted for installation depths from 5 to 40 metres.

Resilient Foam-Filled Float Construction

The float body combines three main structural elements:

• Polyurethane Elastomer Skin
• Stainless Steel Internal Frame
• Non-Water-Absorbing Resilient Foam Material

The internal frame supports the upper structure and mooring loads, while the foam-filled construction helps maintain the buoy’s flotation performance. The resilient Polyurethane exterior provides a practical outer surface for long-term marine operation.

Dimensions and Main Structure

The correct mooring arrangement is essential to the buoy’s operating position and stability.

For the reference configuration, the HNF2.4 supports anchor-chain diameters from 28 to 38 mm and a 5-tonne C35 concrete sinker. The final chain, connection hardware and sinker arrangement should be confirmed according to:

• Installation water depth
• Wind and current conditions
• Wave exposure
• Seabed conditions
• Inspection and maintenance requirements

This allows the buoy and mooring system to be matched before deployment rather than selected as separate components.

The HNF2.4 can be configured for:

• Major channel marking
• Port approaches and harbour entrances
• Coastal navigation marking
• Offshore navigation marks
• Special and hazard marking
• Exposed sites requiring a large visual profile
• Projects requiring a high-buoyancy AtoN platform

Configured for the Required IALA Mark

The topmark helps identify the buoy’s function during daylight.

Dexonmarine can configure the buoy with the appropriate IALA topmark, colour and light characteristic for lateral, cardinal, special, isolated danger, safe water or emergency wreck marking, according to Region A or Region B and local authority requirements.

IALA topmark Option

Port-hand Mark	Starboard-hand mark
Region A Port-hand mark: Red Starboard-hand mark: Green	Region B Port-hand mark: Green Starboard-hand mark: Red

North	East	South	West
Safe Water North	Safe Water East	Safe Water South	Safe Water West

Special Area

Danger all around

Safe water all around

New wreck

Dexonmarine can supply the HNF2.4 as a complete navigation buoy system, including:

• Polyurethane Elastomer buoy structure
• Topmark and daymark arrangement
• Solar-powered LED marine lantern
• Lantern mounting structure
• Anchor chain and connection hardware
• Concrete sinker arrangement
• Project-specific colour and light characteristics
• Final production drawing and supply scope

Before production, Dexonmarine reviews the buoy structure, selected AtoN equipment, mooring arrangement, water depth and environmental requirements as one system configuration. This helps ensure that the main components are properly matched before deployment.

The float uses a Polyurethane Elastomer Skin over a Stainless Steel Internal Frame and non-water-absorbing resilient foam material.

The mooring system is selected according to the water depth, current, wind, wave exposure, seabed conditions and required operating position.

Yes. The colour, topmark and lantern characteristic can be configured according to the required navigation mark and local authority requirements.