Bites without hookups can be caused by many things.
Hooks not sharp
Hooks and/or baits too big
Hooks not protruding from your bait enough
Wrong type of hook for the species and/or rig.
Sometimes the fish will be very tentative and drop the bait as soon as they feel any resistance. Try long, light traces if you think that is happening. Also try a running rig and plenty of slack line if weather and surf allow.