Where are you? A good place to try is Mexico - Isla Mujeres - Yachties heading North generally have no further need for their charts. An excellent book to get is Cruising Guide toBelize and Mexico's Carribean Coast - Capt Freya Rauscher. Loads of info.
#213022 - 04/28/0612:23 PMRe: Nautical Charts for Belizean Waters
I have the book and the charts aren't bad but sailing is still very visual here unless you are in open areas. The text content of the book is fairly out of date but Freya will be coming down this summer to do an update. Lat and Long on the charts will not match your GPS as the charts were done incorrectly by the Brits back in '28 and everyone copied them verbatim after that. There is an electronic re-mapping of the entire coast due to start sometime this year but it will probably be a few years before it's readily available.
#213025 - 04/30/0608:09 AMRe: Nautical Charts for Belizean Waters