On Mon, 18 Sep 2006 11:56:53 -0400, "Bill Kearney"
wrote:

Since this feature
requires rotating and zooming the chart data to match the radar
display, vector charts are clearly the right choice.

Hmmm, no it doesn't. At least not on a Raymarine E-80. I can overlay radar
on top of charts in any orientation. I tend to prefer North up orientation,
but the admiral likes it to rotate with the heading. It's a snap to change
between them.

I agree that it is theoretically possible to rotate the radar image
instead of the chart image. In practice however, virtually everyone
is used to looking at radar images in "heading up" format.