mashworth: After the sunrise event this morning I took the opportunity to visit this one - nominally with the intention of replacing it. I would have done just that if it had only been decimated - as Sjrwilliams' log suggests - but alas the stump which was over waist high when originally placed & knee high last time I visited is now just a (small) pile of rotting wood! Add in the yapping dogs in the adjacent garden drawing attention to us & it was clear that this is no longer a suitable place for a cache, so time to let it go.
Thanks to all who have tackled the puzzle - which was about German U-boats.