The IoW Randonnee is an annual free to enter cycling event comprising a marshalled 100km circuit of the island, with checkpoints and feeding stations. Never having done "the ton", this ride has been on my hit list for a while now, and various factors mean 2013 will be my last opportunity for a couple of years, so I'm in- care to join me?
Obviously not one for the faint hearted, pre-registration is now closed though I understand you can register on the day. The above map gives the route, although it will be done clockwise this year. There is over 3500' of climbing, although it's in short sharp bursts, and the only 2 big hills come at the southern tip of the island, around 30 miles in, when we should be nicely warmed up but with plenty left in our legs :-)
My revised plan is to catch the 07:41 train from Guildford station, which connects with the 09:15 ferry from Portsmouth to Ryde as a foot passenger. We'll each circumnavigate at our own pace, so it's down to you what time you get home- I'm hoping to be back in time for dinner :-)