Board Thread:Warhammer 40k General Discussion/@comment-24821739-20140604204305/@comment-4851119-20140717074205

Well, without the astronomican to guide them they can't "steer" or go long distances in the Warp, they'll have to make series of short jumps (which given the time dilation of Warp time vs real time might actually knock a few weeks off very long distance trips) and only navigate what direction they're going in while in realspace since there's no waypoint to measure from in the Warp anymore, unless they somehow figure out how to use the Eye (which according to at least one novel is very visible to Navigators as a rather distinct purple blob in the Warp) as the center of a new co-ordinate system... but given that without Emps the Eye will have massively expanded and probably block most of their view of anything important anyway.