Very much looking forward to this - although I'm hoping the forecast rain holds off.
I've explored various bits of the Hoo peninsula on foot, but never by bike (though various West Kent members OTP regularly ride out that way). Definitely second the recommendation to visit Grain beach - and if the tide is out (low tide tomorrow is about 1.30pm) you can walk all the way along the causeway to the
Grain Battery Tower. And from there, it's just a short swim to Sheerness...
Also agreed about the Sheppey cycle path. That road really is horrendous for cycling and the path has made it so much more pleasant.
As an addendum to adamski's email, the Horseshoe & Castle in Cooling purports to be the pub that the Three Jolly Bargemen in Great Expectations is based on, where Jaggers meets Pip for the first time (although the old building burnt down and the current building postdates Dickens).
I'm in the 8.40 start group so don't expect to see many other riders until the finish. My train is due in at Greenwich at 08.17, which is pretty much perfect - time to get a coffee before rolling over to the start.