Seatalk is faster than NMEA since SeaTalk uses much shorter "sentences".
But in the case of a Raymarine radar and the smart heading sensor:
the NMEA output of the compass needs to be connected to the NMEA input on
the radar.
The reason for this is to get good arpa and overlay performanec which both
require
fast heading. The NMEA output on the compass outputs just heading data at
a rate of 10Hz. Seatalk would be able to do this aswell but there are also a
lot of
other data on the Seatalk bus.

TomS.

Larry W4CSC wrote in message
...
On Fri, 12 Sep 2003 10:15:18 -0400, drewr3737atnowhere wrote:

I know the SeaTalk transmits more information than the
NMEA ouptut, and one function I would like is the ability for the
autpilot to follow the wind, rather than a fixed GPS point. Is this
possible with the Navman equipment?

This is just not true. NMEA0183 at 4800 baud is lots faster than
Seatalk. Case in point - I just installed Raymarine's new Pathfinder
Smart Heading Sensor (gyro-stabilized fluxgate). Right in the manual
it says SeaTalk will get 2-3 updates/second but REQUIRES me to hook up
the NMEA output of it to one of the two NMEA inputs to the RL70CRC
Plus radar/chartplotter display to get 10 updates per second. They
only use the proprietary SeaTalk data path to setup and calibrate the
sensors.

Is the Raymarine bundle an "end of life" that is being sold off so
that a new, better product is on the way?

I don't think so. Raymarine just came out with a new sonar module for
it all. There are lots of software/firmware upgrades ($44 to upgrade
our RL70CRC Plus from v1.04 to v4,09 was ordered through Sailnet today
to make the display talk to the heading sensor).


Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?