Electronic Chart Update Question

[CaptH]

How do electronic charts get updated with bouy changes? This question came up when discussing buying an electronic chart. Are certain brands dated. Does Navionics have a chart that is more updated than C-Map. When purchasing a Garmin chart such as US005R is there a version I should consider versus this chart 3 years ago? Any information would help everyone on this board.

[tuna1]

All the big 3 update their product one time a year.It appears your thinking electronics replace paper--No it doesn't, it supplements paper,always have both on board.Then update your paper with the Notices to Mariners as needed for the area's you run. Don't fall in the trap of only trusting the electronic"s.