I walked right around the Island of Guernsey, which was about 45 miles using the cliff paths. Though I walked further than that in total, what with getting lost and walking to and from the bus stops for the start and end of each leg.
I might edit this post later on with some links to pictures I took, but for now I just wanted to post that I did it. I had to go all out on the 5th and 6th days to get all the way around in time, the main difficulty was all the steps, especially around the south coast, hundreds of them and made progress slow.
I have been home a day now and the blisters on my feet are starting to go down and I am pleased its something I have done.