That might be something to ask C-map. They might or might not tell you their future plans. For relief charts right now only C-map and TZT3 PBG are options. Depending on the area there might be bathy line charts available for purchase. I alway recommend contacting Tech Support with the Lat/Lon and see what examples they might suggest. MapMedia is working through the available database of CMOR offerings, so if CMOR has that area now, it should be long before MapMedia offers it.