Anyway, enough digression. The problem is this: it seems that anyone who has a boat takes it out in the Solent in the Spring Bank holiday weekend (and at Cowes week too, but Vagabond will be long gone by then). This means that there will be a fair chance of walking across bits of it without getting wet (or needing Divine intervention) and the more popular "parking" spots will be full by midday. Vagabond should be able to take advantage of her small draught and anchor near the High Water mark if necessary.
This map (based on Admiralty chart 0001) shows the planned route: