Subspace Sandbar
During the The Duronis System Sandbar Incident a vast quantity of information on the Subspace Sandbar was uncovered. For more information on the layout of the sandbar please see also Duronis Spacial Geography
Subspace Sandbars are a phenomenon which prevents a vessel using warp drive at all within a given region - essentially, a region with a Cochrane factor of zero. These regions are, fortunately, very rare.
This information is courtesy of the Daystrom Institute Technical Library and copyright Graham Kennedy.