Rowland Reserve in Bayview is the best dog beach / dog park in Sydney!
It has a large green area to run and play with drinking water in the middle. The beach itself offers plenty of space to run, chase and wrestle. Water access is great and you can easily join your pup for a swim. During the weekend dog washing services are available in the park.
Drive (or swim?) to the dog friendly pub Newport across the water for a relaxing drink 🙂