I agree that it makes the most sense for Gillian to stay with the whales. However, Star Trek isn't always, dare I say it, logical. Perhaps Starfleet wanted her to check out some of the other cetacean lifeforms on other planets and they reassured her that the whales would be taken care of while she was gone.
Taken care of by whom??? Gillian Taylor is the only humpback whale expert in the entire
galaxy at this point. Like I keep saying, nobody else is qualified. (And yes, there may be other whale species extant, but it's not like they're interchangeable. Each species no doubt has its own distinct requirements.)
Besides, like I said, it would be completely out of character. Gillian's whole arc in the movie was driven by her passionate devotion to the whales. She didn't come to the future to explore space or to hang out with Jim Kirk, she came
in order to stay with George and Gracie and take care of them. That was her entire motivation in the film -- why would it suddenly change?
I may be misremembering, but didn't she also say that she was going to a water planet to recruit divers, presumably to work with the whales.
I don't know where you might have heard that. It's certainly not in the film. And it's a strange rationalization, because
Earth is a water planet. It's 71 percent water by surface area. There are plenty of expert divers right here.
Even so, she also said she was doing some catch up learning. Despite her experience with living whales, there would still be vast amounts of biological and technological science that she'd be unaware of. She could easily be using the trip to focus on areas to deal with the whales and return in time for the birth.
But why would she have to go into space to do that? Why wouldn't that education be available on Earth itself? Earth is still the home of most of humanity in the Trek universe, the capital of the Federation, the political and cultural center for all of humanity. If Gillian wants to learn about how to live as a human in the 23rd century, how is Earth not the best possible place to get that education?
While Christopher is right that it didn't make much sense for her to fly off on a spaceship I think it's exactly what the writers of the movie meant.
I don't see any reason to assume that. All she said was "science vessel." The word "vessel" applies just as much to a seagoing craft as a spacecraft. It's only the viewers' assumption that it meant a spacecraft. We have no proof it's what the filmmakers intended.
And no, "See you around the galaxy" doesn't count, because it's too figurative. It struck me more as an acknowledgment of Kirk's life as a space traveller than a literal assertion of Gillian's own intentions. In the context of her entire characterization throughout the movie as someone devoted to George and Gracie above all else, I just don't see any character logic whereby she'd suddenly forget all that and go into space.
She didn't mention anything with respect to her ship assignment about bringing a new whale into the world at all.
Why would she need to? We'd just finished watching a whole movie in which her overriding motivation as a character was clearly defined as the desire to care for George and Gracie. Why would she need to state that her personality hasn't abruptly undergone a complete transformation? It should be implicit.
Of course, she doesn't say when she is to report to her science vessel. Perhaps that is after helping to bear a new whale, and she is smartly planning her future not to revolve around a man.
What??? That's a total non sequitur. How would staying on Earth mean her life was revolving around a man? If anything, it's the other way around. If she gave up her whole identity as a marine biologist to follow Kirk into space,
that would be writing her as merely an extension of a man. Staying on Earth to care for the whales means staying true to her own motivations, leading her own life independent of what Kirk might have imagined or wanted. And that's completely in character as well. Kirk may have flirted with her somewhat in the film, but it seems to me that he bombed pretty completely, because she was too devoted to her career and her cause to be interested in romance (and perhaps because he was a couple of decades too old for her anyway).
But then again, she is evidently already in uniform.
Huh? She's wearing some kind of 23rd-century outfit, but we don't know it's a uniform. And even if it is, maybe it's the uniform of the ocean vessel she's signed onto. It's not Starfleet, after all, and there's no reason to assume that Earthbound institutions in the 23rd century have universally abandoned the practice of wearing uniforms.