Christies Creek flows across the middle of the beach and separates Christies Beach from O'Sullivan Beach. The northern sewer works are fronted by a low sand dune, with the breakwater of a boat launching harbour forming the northern boundary. Both beaches receive low ocean swell as well as gulf wind waves, with waves averaging 0.5 to 1m. This is sufficient to produce a single bar, usually cut by rips every 200m. The centre of Christies Beach, where the surf club is located, is partly protected by Horseshoe Reef, which lies 300m offshore. This causes the beach to protrude seaward at this point and receive slightly lower waves.