Hello: Glad to see Furuno's support for a website. I purchased a Navnet 3D mmfd12, it came with many charts preloaded. Some are "included" and some are "locked". I want to sort thru the charts to delete ones I will not use, add ones I plan to use, and "unlock" ones that I may also use. I wrote down all the preloaded chart numbers (some 40 or 50),by chart number such as SDRO1PO1MAP01 (which is locked). How can I efficiently sort thru these to determine their area of coverage to determine if I want to keep it or delete it? The furuno wbsite does not seem to have such a listing by chart numer.