Helmut, Any southern California beach is good for corbina during the summer months. Time of day that is best depends upon the beach itself, the corbina, and the sand crabs. Visit the beach when you have time to spend and note when the sand crab beds are washed by wave action. Extreme lows leave the crabs high and dry up the beach. Extreme highs completely cover the crabs and the wave action disturbs them little (nothing washed out to the fish). Now you know when... Cast your bait right into the middle of a crab bed (it may be exposed sand as the wave recedes). Let the wave move the bait around.
Bill