They call him up from the galley.
"We just saw it, and didn't want you to miss him fly by," was all they said.
Sky Bison off the port bow.
Bumi laughed, shaking his head as he stood and made his way above deck. His smile fell however, when he looked up and noticed Appa had no rider and no saddle. It wasn't like the old boy to just wander off, which meant...oh. Oh no.
Without word Bumi turned to go back in the direction he'd just come from, moving below deck again towards his quarters. He packed in earnest. This wasn't his father zipping past, or stopping by for a visit, this was something else entirely.
The ship rocked as the ten ton sky bison landed with a thud on the main deck. Bumi appeared moments later, a small bag slung over one shoulder.
"Commander, what are you doing?"
"Leaving."
"But you can't just...go."
"Watch me."
"Your command!"
"Relieve me of it. Label me a deserter or a traitor, I don't care which. Do what ever you like. I'm getting off this boat."
He doesn't look back, Bumi stays his course towards the sky bison, who lowers just enough to allow the man to climb onto its back.
If it wasn't bad they would have messaged.
If it wasn't urgent Appa wouldn't have come.
If it wasn't life threatening Kya would be there to keep him company during the trip.
When Bumi is seated comfortably on Appa's neck he looks up to find that his entire crew has appeared to see him off. He sits up straight and offers them a salute, which they all return once they too have found their way to attention.
"Yip yip," he says and Appa's tail comes crashing down down for lift off.
As they rise into the clouds and head towards Air Temple Island Bumi knows that is father is dying.