It really is dependent on the spot and conditions.
Low tide you can sometimes get closer to the drop which you won't clear with a cast on high tide.
High tide the sharks can access areas which are cut off by banks on the low tide.
Pushing tide can bring bait fish / sharks in closer but can also push in cold water in which isn't always good.
Dropping tide can push bait fish offs banks which concentrate the sharks near the drop offs.
Sometimes the in between tides are best when the water is moving, when it's dead low or high the fishing goes equally dead.
Sometimes it really doesn't matter...
This really goes on and on, and often other factors such as kelp, seaweed, fresh water from estuaries etc also play a big role.