Not even being subtle 
Also in the same scene they allude to a coming Zeon civil war (classic fascist infighting), which kinda adds higher stakes to Challia's quest to find the Red Comet.
Another banger episode, although we just speed ran a whole bunch of UC tropes all at once. Shiiko's a pretty good antagonist, and the stuff that happens in this episode is really going to push the main cast in interesting directions, so I'm all for what they're putting down even if it's a bit familiar- Tsurumaki was really channeling his inner Tomino in that (admittedly very cool) dogfight, right down to the comic panel cut-ins and dialogue.
(Also, something tells me that if they're in a rush to get through all this kind of story stuff early on, that they're planning some wild swings later, but that's just a hunch).
Remember,
Non-jokey answer: Machu really really wants to swim in a real sea- she feels constrained and alienated by life in the colony, and is searching for something authentic and real that in her head she visualizes as a sort of idealized version of earth and its oceans.