The premise of a physical sextant on a starship is that the navigator can pick out the same stars at both the departure point and the arrival point, and measure their angles, to determine the ship's new position. However, there are a number of fundamental problems with this notion. Constellations become distorted in as short a distance as a third of a Jump 1 distance; over a full Jump 1 distance, or even a Jump 2 distance, the constellation may be unrecognizable. So you can't pick out a star by its approximate position in the constellation. The brightness of stars changes over distance. Picking out stars with the correct brightness is not something easily done by estimation due to the inverse-square law. Local cloud features of the star system may also interfere with this guesswork. The color of stars can change due to dopplar shift from the relative velocity of the arrival point to the departure point, and due to local cloud features interfering with the color. All of this leads to it being very implausible that an alien species with features that are at all Earth-like would ever be able to pick out stars manually. The case can be made, though, for alien species that: Have natural hyperspectral vision that can pick out elemental spectra from the star light, and identify the right stars by their component and interfering elements Have a natural means to detect pulsars and their frequencies Well, what about the case where the physical sextant is just a robotic arm mounted sensor? Well, that's implausible because: In order to take the most useful measurements, the sensors would have to be mounted in as close to a completely spherical transparent housing as possible, and as far out from the center of the ship as any of the furthest available points on the hull; putting it inside a "room" of the ship, with opaque deck in the way, robs the system of valuable accuracy. They would be mounted in a gimbal, for rigidity and reliability; a "robotic arm mounted sensor" would add unnecessary noise to the angle calculations, and would be a genuinely poor design, except as a user interface to capture manually targeted readings; the noise would still be bad in that case, but it would be more comfortable to manipulate; but since the user can't helpfully pick out stars to begin with... All of this leads me to conclude that the sextant device is a wasteful art piece, rather than something with any practical purpose, since ship sensors and the navigation program would generally be much better at the same job. Even in the case of a culture with rudimentary sensor technology, where the sensor has to be pointed in order to scan the entire sky, a gimbal is a much more appropriate mounting choice. An alternate theory is that the sextant is there as a conceptual teaching tool, for explaining the theory behind navigational triangulation, rather than implementing navigational triangulation itself. In which case, we could be on some kind of trainee ship for fresh recruits. Please bear in mind, this is by no means a criticism of the GM; the author of the module, perhaps, if it turns out there is no plausible justification for this "piece of background fluff". Rather, I'm just trying to take the information at face value, and see what I can glean about the ship, it's inhabitants, and its creators from analyzing it all, and hoping that the GM will consider revising the details in the face of their implications as warranted. Finally, it's important to note that space navigation itself is almost entirely an application of software rather than a meaningful skill; while it may merit an instrument panel and an interface, it by no means merits an actual physical station, requiring an additional person to man it. With the equipment to move it and the sensors to take the required readings, a monkey with a smart phone could navigate the universe, even under practical constraints. :P Now, granted, Navigation skill is very important as backup in case the Navigation System or Sensors fail; but otherwise, it's completely meaningless.
