Superhydrous B (shy B), is a dense hydrous magnesium silicate (DHMS) which exhibits a large stability field in cold slab conditions. It was deformed at 20GPa and at temperatures 1000-1100°C. The resulting dislocations have been characterized by transmission electron microscopy (TEM) with the weak beam dark field (WBDF) and the large angle convergent beam electron diffraction (LACBED) techniques. We emphasize the role of   010 plane in the plasticity of phase Shy B. We report that   100 and   001 glide in   010 , and also climb of   100. We also observe 101 glide in   010 and   111 planes under high stress conditions.