Deepdene Beach is a 5.3-kilometer stretch of coastline within the Shire of Augusta Margaret River, Western Australia, terminating in the lee of Cape Hamelin. The beach is characterized by its significant length, backed by vegetated dunes that rise to a maximum of 173 meters and extend up to 4 kilometers inland. The southern half features extensive beachrock, which creates numerous tidal pools and some permanent rips along the shore. The northern half is free of beachrock but has more persistent beach rips spaced approximately every 300-400 meters. A small permanent rip against the northern boundary rocks provides the most accessible surf breaks. Wave energy increases toward the north, averaging just over 1.5 meters along the northern few kilometers. Scattered reefs extend 2 kilometers off Cape Hamelin, contributing to the area's structure. Turner Brook drains across the beach approximately 1 kilometer southeast of the cape. The Caves Road runs along the eastern boundary of the dunes, with a camping area located in the dune area behind the northern end of the beach.