On Tue, 6 Apr 2010 15:50:31 -0700, "nom=de=plume"
wrote:

Center axis or mid-point (both vertically and horizontally would be an
issue), so the axis must be in the center of the channel.

There is no channel, the Gulf Stream is free running although it
favors the deeper water off the continental shelf. Center axis and
mid-point have approximately the same meaning applied to the stream;
it is basically the region of strongest current flow and it varies
over time as the stream meanders. The farther you get from the center
axis/mid-point, the weaker the current. The eastern edge of the
stream is constrained by the Bahamas Banks, approximately 40 miles
from the center axis, the western edge of the stream is constrained by
the Florida shore which at times is only 6 to 8 miles off axis.