First and most frustrating cache of the day. Simon was also harbouring a bad back, and had hardly slept the night before, which didn't make things any easier. Still, we found 4/5 overall, so we are happy in the end.
The problem was the GPS reception: there basically was none, and, even when we did see a few sats, the results were not to be trusted. Also, there was a bunch of climbing groups out, and we fear that one of those groups may have been "hiding" the cache location.
Never mind. Maybe we will have the opportunity to try again sometime.