The cache is not at the indicated location. You will need to do research beforehand to find it, but this is the simplest of puzzle caches. The coordinates are not in other caches on the loop.
Assume N52 56 and W1 19
both Seaman + James + van der Saar + Howard + Given
Pepe + Kasper's Dad + Sorensen
You can check your answers for this puzzle on GeoChecker.com.
please do feel to mail me if there are any problems with any of the caches on this route.
If you hate puzzle caches then download the route map pdf for the series as it contains a walk through for this puzzle.