emu, it may not fly but it is bretty dam big ( knowing this I'm from AUS)
A swan is an aquatic bird with white feathers
A possible word is pelican, a large aquatic bird.
An aquatic bird is basically called an aquatic bird.
A swan
A penguin may be the most suitable answer, but a loon is a consideration.
Gannet
Probably an Albatross.
Blue bird
Albatross
It is a large sea bird that is often white with black at the end of their wings.
black vulture
The bird described is a coot. There are 12 extant (living) species of coot.