This is the final cache of Little Duck's Journey. Needless to say, the co-ordinates given are NOT for the actual cache. However, if by now you are becoming a thirsty duck – and a thirsty duck is, of course, a terrible thing – they are for an establishment where this parlous state of affairs may be rectified.
To find this cache, you will need to complete the other caches in the series, which are, in order from the suggested parking:
GC3YK3P Heron – Little Duck's Journey
GC3YK7Z Fisherman – Little Duck's Journey
GC3YK8A Swan – Little Duck's Journey
GC3YKG0 Canoeist – Little Duck's Journey
. . . and have a little think about the information you will find in these caches.
As explained at the start of the series, you are looking for the narrowboat "Wild Goose", where Little Duck's Mum is hanging around scrounging food. This is a fictional boat, as are the rest of the boats in the puzzle, so paddling up and down the cut looking for it really won't help! 
“Aaargh,” quacked Little Duck, “all this time, I've been swimming the wrong way!” But on the plus side, he knew where to go now. Back past the sleeping swan, back past the fisherman . . . he even waved to the canoeist, who had just dropped his boat on his own foot while trying to load it onto his car. Round another bend in the canal and there was a narrowboat, with a cluster of ducks round a little boy flicking bits of bread off the stern. “Mum! Mum! I'm here!” quacked Little Duck.
His mother disengaged herself from the feathery feeding frenzy. “Ah, there you are, Little Duck. I was starting to wonder where you'd got to.” And she gave him a big feathery hug. ::o)
IMPORTANT SAFETY NOTE
The caches in the series were set from the point of view of a small duck. If you are not a duck, you will need to equip yourself with something with duck-like properties, such as a canoe, kayak or other small boat. The caches are NOT accessible from the towpath and if you try you will probably land on your head in the canal.
As always, if you are not completely confident in your ability to access the cache safely, either enlist the help of someone who does know what they're doing, or give up and go to the pub instead. You cache at your own risk. Don't do anything your mother wouldn't do.