I like the idea of physical shutters slamming down, with an audible clang, over view ports. These barriers should be formidable and sturdy bearing caveats in bright red letters that begin "INTENTIARE!", contain shrill, imperative language and are illustrated by icons depicting madness and death. During warp-travel cogitators and auspex simply relate non-sensical or outrightly deceptive (or worse than useless) information. The navigators' occulus is available observation dome for navigators, if I am not mistaken. Of course, the occulus must also be protected by the gellar field or it would be a constant weak point for incursion by warp entities. Maybe it is? For their purpose, I would believe the gellar field doesn't hinder normal vision, unless the navigator-gene allowing them to pierce this veil.
However, staring into the Warp by the uninitiated even through the tint of the gellar field would result in accumulating corruption and insanity points, along with of a kind of warp-viewing addiction. The horror: the more you look at it, the more you want to . . .
Ship-based Endeavor: A small band of crew-members who have deactivated the shutters in their section in order to view what lies beyond, perhaps as a test of courage, just simple curiousity, etc. Maybe they presume the gellar field will protect them? Eventually they are compelled to partake of a pure, unadulterated eyeful of the Warp and take steps to make a small hole in the field; just for a peek, you know? A simple little peep. Just a few seconds-- What could happen . . .?
Let him who is with sin cast the first plasma bolt. - Warmaster Picklehauber