That's a very smart concern to have! Living near the ocean is wonderful, but the salt air and moisture are brutal on ordinary materials. You're right to think about this before your bin becomes a rusty, corroded mess. For your location, the absolute best material is stainless steel (specifically grade 304 or 316). Look for bins labeled "marine-grade" or "saltwater-resistant." The higher chromium content creates a passive layer that fiercely resists salt corrosion. It's the top-tier, longest-lasting choice, though it comes with a higher price tag.
A fantastic and often more affordable alternative is high-quality, UV-stabilized plastic/polymer. Modern resins, like those used for marine equipment, are engineered to withstand salt, sun, and won't rust ever. Ensure it's heavy-duty with thick walls. Avoid thin, cheap plastic that becomes brittle.
Materials to avoid are standard galvanized steel (the zinc coating will eventually wear off near the ocean, leading to rust) and basic powder-coated metal (chips and scratches from use will let salt in, causing hidden rust underneath).
A quick tip: No matter the material, choose a bin with a tight-fitting lid to keep out salty moisture and rain. Placing it in a slightly sheltered spot, if possible, will also add years to its life. Opting for stainless or robust plastic now will save you from frequent replacements down the line. Enjoy the beach views without the rusty eyesore!