on some humminbird units they have nvb on them , it costs more , what exactly is nvb?

NVB=Navionics bundle. Installed maps. My bundle is Gold + and Hotspots.

thanks canepole, so i really dont need the nvb package if i already have platinum maps right?

Thats correct. & NVB is all 2006 year maps, there has not been a update to it. Only way to update a nvb map package is buy all new SDmap cards and unit will automatically read the newest chip.