Any technology that can generate artificial gravity fields inside a spacecraft can "plausibly" (in-story) be adapted to provide bouyancy in a gravity field. Star Trek/Wars, BSG, etc. are at least somewhat internally consistent in this matter. ID$4 had so much wrong with it that this one detail hardly stands out.

Franchises with solid "forcefields" also sometimes use the excuse that they shape their shields around a non-aerodynamic vessel to provide a smoother ride, but it's a damn stupid and wasteful design.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
"The Mayan symbol for "book" looks a lot like a triple hamburger, but I've never seen them claiming it as proof the Mayans had Big Macs." - KaiYeves
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