That's a great and very practical question for anyone living near the coast! The short answer is: for most coastal areas with salty, corrosive air, a high-quality plastic waste bin is generally the better and more worry-free choice. Here’s why.
The main enemy in coastal environments is salt spray and humidity, which accelerate corrosion, especially in metals. While stainless steel can resist it, standard galvanized or painted metal bins are highly susceptible to rust. Once the protective coating chips or scratches—which happens easily—rust sets in, leading to unsightly stains, structural weakness, and a much shorter lifespan.
Plastic bins, particularly those made from UV-stabilized polyethylene (like those used for marine equipment), are inherently immune to rust and corrosion. They won't deteriorate from salt exposure alone. Modern plastics are also durable against impacts and don't dent like metal. The concern with plastic is UV degradation, but quality bins are formulated to resist sunlight, maintaining their integrity and color for years.
Maintenance is another key point. Plastic simply needs rinsing with fresh water to remove salt residue. A metal bin requires more vigilant care to check for and touch up any scratches in its finish to prevent rust spots.
That said, if you prefer metal, invest in marine-grade 304 or 316 stainless steel. It's excellent but comes at a significantly higher cost. For most public spaces, parks, or residential use, a heavy-duty plastic bin offers the best balance of corrosion resistance, durability, cost-effectiveness, and low maintenance in salty air. It’s the set-and-forget option that lets you enjoy the sea view without worrying about a rusting eyesore.