buy Molly her own Paslode ya "cheapskate".....

...
(only kidding)..........
it could be the colour (brightness of the Orange) as dogs see colours different to humans,
collies are always quite highly strung if not worked....(see own Paslode ..again).. they need to be kept stimulated..... thats one of the reasons i stopped having Collies as pets... not the time needed to keep them occupied.....
as for the pond, if a dog feels threatened in anyway shape or form, they need to "hide!!" and the best way to hide for a dog is to cover your scent.. hence the smelly mud!! or cow dung is another dog favorite!!! (also helps them, if a country dog go "un-noticed" in another dogs territory!!)
not a great lover of live in dog training, as it really needs to be interaction with the owner and the dog concerned to be able to train the pair as Alpha, and subversant animal!
dog (pet- not working) training is all about getting the dog to be subversant to the MAIN owner/handler, and quite a bit of the time it is down to how the owner and the dog interact together... who's boss and who is not....
Many years ago, when living right on the coast, and having the time to have more than one dog, i used to help out at the 2 local dog training Societies, and so often it was 60-80% of the time how the owners responded to /commanded the dogs!!!!!
but like i stated earlier,Collies are such clever ACTIVE dogs, the need constant stimuli to stop them basically getting bored!!!!
p.s, still buy Mollie her own nail gun!!!!

( hang on that could be it,...she reckons you should have bought a Senco/Ace & K AIR nailer, and shes trying to get you to dump the old hissy Passy!!!!!!!!!!!!

)