The Adelaide spots inside the St Vincent Gulf are very tide reliant, working best on mid-high tide, on the push. Big swells from the right direction are needed and summers are mainly flat, so don't expect waves over 5ft (1.6m). The Esplanade makes coastal access easy, with lots of car parks. If there is a major storm with gusty SW winds, the reef at Christies Beach will have uncomplicated lefts and rights that work at low tide and only manage to get to about headhigh on a decent swell. Also try Y-Steps or the Hump, where refraction can make A-frames pop up, which should have a bit of power.
The shark threat is real, more so at the reef.