mark near estuary

fishing a shallow rock mark around 750metres from mouth of an estuary, the mark fishes well from low water to around 3hours before high tide and then dies. would bass be heading for the estuary a few hours before high tide?

I would say without doubt thats what they are doing. I have found it varies from one estuary to another. Trial and error and take a note of your catches. One estuary i fish the Bass enter it 3 hours into the rise, and I will catch them 2-3 hours after full on the way out again. I catch more during the 2-3 hours after high so I guess that I am missing some of them on the way in, in general. Obviously we cannot tell when each fish will enter and so on and im sure they dont all enter around the same time. I know of another estuary that as soon as the tide turns the Bass leave with haste. Also depends on depth of water, speed of water and even air pressure. I have kept a record of every bass I have ever caught so over the years it has been easy for me to look at patterns and work out what they are doing.

i fish a very similar spot mainly for ST but have caught the odd bass (best 7lb), again from low water to 2 hours up, after which there's nothing. The mark is rocky and very weedy, and I've often wondered if the pattern is due to tiny prey species concentrating under the drying weed at low water and then starting to move out as the level begins to rise and the weed floats up. The 7lber was hooked in 2ft of water as it was nosing under the weed, and its belly was fully of tiny hardbacks.
Also notice the mark fishes best when low is at the end of a warm day, presumably the rocks heat up and the fish move in to bask in the warmth.