Oddly enough, that gathering of geese in flight is a wedge. When they aren’t in formation, but still in flight, they are skein or a team. When flying close together, a plump. On the ground, a flock or gaggle and in water, just a gaggle.

Ducks in the water you ask. A paddlington.
Unless they are close together. Then they’re a raft.

And coots? A floatila apparently. Guessing only when they are in water.