PolyAl in marine and aquaculture: pontoons, fenders and floating walkways

The marine environment is brutal: UV, salt, abrasion, biofouling, freeze-thaw cycles, hurricane stress. Most plastic compounds fail within 5 years. PolyAl, by contrast, has been performing in Mediterranean and Atlantic marinas since 2018 with no documented structural failures.

Why PolyAl works in the sea

• Hydrolysis resistance: polyethylene is one of the most hydrolytically stable polymers known
• Aluminium reflective UV barrier: protects the bulk from photo-oxidation
• Closed-cell, no water absorption: < 0.05 % water uptake at 24 h
• Biofouling: smooth surface and low surface energy reduce algae and barnacle adhesion vs concrete and timber
• Freeze-thaw: no water inside the matrix means no expansion damage

Applications in production

• Modular floating pontoons: replace timber decking on marina walkways. PolyAl planks 140×35 mm on aluminium frames, 25-year warranty achievable.
• Dock fenders: rotomoulded hollow profiles filled with closed-cell foam.
• Aquaculture cage walkways: salmon and sea bass farms in Norway, Greece, Chile.
• Floating photovoltaic floats: structural floats supporting solar panels on calm waters.
• Marina cleats and bollards: injection-moulded with stainless inserts.

Spec considerations

• Add 1.5 % carbon black + 0.3 % HALS for marine UV stabilisation
• Use stainless 316 fasteners; standard 304 corrodes in spray zones
• Design for thermal expansion (PolyAl: 1.1 mm/m per 10 °C); leave 4–6 mm gaps on decking

Compliance

• ISO 13628 for offshore plastic components (where applicable)
• Lloyd's Register and DNV provisional certification available for floating PV applications
• IMO MARPOL: PolyAl is a registered, traceable industrial material — no microplastic concerns under standard installation

Marine engineers who have switched from FRP and tropical hardwood to PolyAl report comparable lifetime, lower maintenance, and a defensible recycled-content story for tender documents.