We're new at the iPad for navigation but from what we can tell it's pretty darn good. We have Garmin Blue Charts. The app is free and charts for both U.S. coasts, including the Great Lakes, Alaska, the Hawaiian Islands & major inland rivers. Coverage includes the Bahamas, the Turks & Caicos Islands, Puerto Rico and the Pacific coast of Canada for $30. They are as accurate as the CMap charts on our laptop and have much better detail for the Bahamas (which is why we bought the iPad) plus you can over lay Active Captain.
Jim: I'd be curious to see how the Garmin CA charts on the iPad compare to what you have.