If you want to get all technical about tides, read this.
Obviously skip the first bit which is about the site, but further down it gets very detailed. Not remotely useful really but nice to know
Best bit, I thought, was about the double high tide at Bournemouth and the surrounding area... which apparently has nothing to do with the Isle of Wight after all...
(Dont bother with this unless you're genuinely interested. It has phrases like 'from harmonic analysis of tidal observations we can determine how the individual harmonic constituents which combine to create the tidal regime' in it...)