On Tue, 28 Jul 2009 08:48:46 -0400, "JR" wrote:

I know of no production boats with the paddle wheel on the centerline.
Regards,
JR

It is usually impractical unless you are willing to live with a
transducer in the middle of your forward cabin sole. In addition to
being exactly on the centerline and precisely aligned, it is also
necessary to be at least a foot or two forward of the keel. We
decided that port and starboard transducers were the best of the bad
choices available. That has its own issues however, not the least of
which is switching on every tack or jibe. It would also be highly
desirable to have separate calibration controls for each transducer
but that is even more difficult in most cases.