Personally I don't bother with bait , but you may have success from a boat targeting them with artlure in shallow water
have a read through
http://sealine.co.za/view_topic.php?id=92685&forum_id=64
http://sealine.co.za/view_topic.php?id=84522&forum_id=64
http://sealine.co.za/view_topic.php?id=73675&forum_id=64