Plastic waste is piling up along our coasts, much of it settling on the seabed. Recreational divers—who explore exactly these shallow zones—rarely carry collection gear, so bottles, toys and plastic fragments are left behind. My project is a social science and behavioural change initiative: I conducted large-scale surveys to find out whether people would accept and use underwater bins. The result is my patent-pending underwater bin—light, safe for marine life, able to filter microplastics, and flat-packed for global shipping and easy on-site assembly. Shore signs mark its location so anyone can take part, from snorkellers to experienced divers. It’s a movement that turns individual effort into shared responsibility—and makes cleaning the ocean as normal as using a bin on land.