Honestly, if I were specifying a bench for a coastal streetscape, I’d choose marine-grade aluminum with a baked-on powder-coated finish. Not just any aluminum — marine-grade aluminum. It won’t rust, it handles salt spray well, and the powder coating keeps it looking clean for years without painting or sealing.
Wood looks nice, but near saltwater it needs real upkeep. Even teak or ipe will weather gray, and if you want to keep the color, you’ll be cleaning or oiling it regularly. Concrete is tough, but it’s porous. In a coastal setting it can absorb salty moisture, and if the internal rebar isn’t properly protected, it can corrode and cause cracking. Painted or galvanized carbon steel is risky too — one scratch near saltwater and rust starts quickly.
316 stainless steel is the premium runner-up. It resists pitting far better than 304 and is extremely strong. The catch is that it isn’t always zero-maintenance. In salt-laden air, 316 can develop light tea staining if it isn’t rinsed occasionally. It also gets hot in direct sun. If you don’t mind an occasional wipe-down and have the budget, it’s a great choice.
But if the goal is truly “install it and ignore it,” marine-grade powder-coated aluminum is the sweet spot. The aluminum itself won’t rust, and a quality marine-grade powder coat protects the surface from that chalky white oxidation aluminum can get over time. Specify 316 stainless steel fasteners and hardware, because mixing metals near saltwater can cause galvanic corrosion. Also look for slatted or perforated seats so water drains and dries fast, and avoid designs with crevices where salty moisture can sit.
One extra tip: go with a lighter color or textured finish if the bench sits in full sun, since metal can get hot. For a coastal urban bench, marine-grade powder-coated aluminum is about as low-maintenance as it gets without paying a premium for stainless steel.