Hey guys can anyone recommend a good place to get some charts for perth metro area through to two rocks.. I currently use my sounder with Navionics gold map to find spots but it is a bit hit and miss and not the kind of deatil I'm looking for. Specifically Im looking for something like a hydrographic chart or something that shows underwater structure like detailed lumps etc... I have seen one once but cant remember what its called or where to get them from. Any help is appreciated.