Home Postcode finder WA Watermans Bay Watermans Bay postcode WA Watermans Bay is a locality in Western Australia covered by postcode 6020. Postcode 6020 State or territory Western Australia (WA) Region Wa Subs 2 Gsr Add a free Watermans Bay business listing Be the first listing in Watermans Bay Common questionsWhat is the postcode for Watermans Bay?Watermans Bay, WA has the postcode 6020.What state is Watermans Bay in?Watermans Bay is in Western Australia (WA).Does postcode 6020 cover more than one suburb?Yes. Postcode 6020 covers 5 localities, so the postcode alone does not identify Watermans Bay. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.