i think you are all right about the clipper, but i think its linked with the O2 stop get off there and look around, i would but i not going to get to london at the mo, i only live in southend but not got much time to take a trip to london at the mo, but i think its not on the clipper but when you get off at the O2 place.
(From Kemble embark the eurofighter T
transporter)This could be linking to the clipper as many have said nothing to do with Kemble (then come forward 4 times, right?)
this might refer to the 4th stop at the o2 area, the right part might be look to your right as you get off at O2.
just something to think about
all this reminds me of the old Channel 4 show treasure hunt , bring back annie