Couple of debating points. Unlike Alan I've never fished it at high tide off either the prom or the beach but it's always the first accessible mark on the beach on the ebb.
Point 1 - during the Tsunami comp, organised by Tim, I fished the BOS and caught 2 fish first two casts, fishing around the group of rocks that you walk past, high and dry, at low tide so there are fish well up the tide.
Point 2 - ages ago, on a weekend trip, I'd got up at 5am to fish the ebb, before setting off back to Cannock so, predictably, I was on the beach on my own. Looking along the beach 2 chaps arrived and started plodging around below the Toilets mark. I had a walk along and they were hauling a net they'd stuck, randomly it appeared, along the beach. They had 2 codling, one about 2lb and one that must have been nearer 15lb. The setting for their net was flat and featureless. The fish were obviously, to me, running along the beach.
Debate? We get in our minds that certain marks fish at certain stages of the tide and in certain conditions and we base this on, sometimes, years of experience but fishing sometimes defies that logic.
Having wrote the book, the year it came out I caught fish on the ebb at one of the marks I said I'd never done previous. I'm sure this has happened to most of us. It doesn't change the odds of catching but it does put doubt in the mind.