The moment she spots her old Pipe Pal (at least, she’s assuming that tiny blue blob has got to be Dory since she doesn’t really know any other fish that specific size and color who swims about this part of the reef with so much enthusiasm so early in the day), Destiny gives the Blue tang a gleeful, bellowing greeting in Whale from where she's drifting just above the corals,
“GOOoooOOOD moOOORrning, DOOorrYYY! HOOwww aaRRe YOOUuuu?”
Obviously, there were no pipes in the ocean. And the only other whale around here was Bailey (who, of course, speaks fluent fish in any case). But it’s not like it wasn't still fun to break out her and Dory’s shared second language every now and then.
Dory had always been sort of a morning fish. Ever since she was a small fry, she always was bright and early and happy. A lot of those mornings she didn't really remember, but right now she was very aware that mornings were great. And that was quite clear as she stopped her humming and turned to her giant, fryhood friend and certified pipe-pal, Destiny! Dory was so in her own head, Destiny may have been able to sneak up on her if the sea around her hadn't moved with her friend's approach.
"GOOOOOoooOOOOd mORrRRniiiiiiNNNNG DEEEEEEEEEEESSSSStiNYYYYYYY! I'MMMMM GooooOOOOOOD! hOOOOWWWWW aREEEE yOOOOOOOOUUUUU?"
That was something that never left Dory, her fluent whale speak. That and cuttlefish, but that was a different story (she believed). And now that she had memories come back of how she first learned it with one of her best friends, it felt even better to use it, especially now that she was all grown up.