It changes almost like clockwork. Storms and bathymetry/landmasses/currents affect it.
There is something called a seiche which is more a thing on lakes or enclosed bodies of water, but there's like a million little seiche-like almost tsunami-like refractions happening in the oceans at any given time.. They are largely noticeable, more than largely, you will never notice these but my point is the myriad of stuff happening on a local and even ocean wide scales at any given time to potentially complicate things.
I think, its like smoke and mirrors illusion if the tides seem to fluctuate from regularity,. Correct me if I'm wrong. Please.
As a kid I used to duck hunt on a tidal river, and the projected times of high tide did fluctuate but generally high tide was an hour and 13 minutes later every day than the day before at least during that duck season on that river.
Tidal waters can get "pent-up" behind a promontory landmass, and then when it gets to a certain height, only then will it continue to spread, which will then affect features down the line in a now, uneven fashion.
I don't really know what I'm talking about, but many of you can think for yourselves. Am I wrong?