Beach erosion and big swell forecast for South Australia prompts warnings to stay away from beaches updated 5 Breaking waves in excess of 10 feet are forecast across SA's ocean coasts. ( Print text only Cancel Beach erosion and extremely hazardous boating conditions are expected across most of the South Australian coast this weekend, with a massive swell prompting the Bureau of Meteorology (BOM) to warn people to stay away from affected cliffs and beaches. Key points: A swell of about 8 metres is expected to peak at Cape du Coedic on Sunday morning The Bureau of Meteorology has warned against boating on late Saturday and throughout Sunday