Personally, I think a Bizer map should be required for all boats on the Big Lake. While I have a Navionics chip on my HDS, I never rely on anything electronic always working. I keep the Bizer and an old school compass handy.
The Bizer will including Blacks Point but I don't think will mention "The Broads" as I'm not sure there is an exact definition of what the Broads is. I'm sure my definition varies from the next guy with my definition being: the mouth of Alton Bay (Black to Rum Point) along the eastern shorelines of Rattlesnake and Welches up to where it narrows between 3 Mile and Black Cat, back down alond the western shoreline of Long Island to the mouth of Wolfboro Bay. I'm sure some definitions will have the Broads ending at 6 Mile Island....others will extend them north to the entrance of Center harbor.