I just bought a Raymarine ST1000 Plus tiller autopilot for my Endeavour 32.
The astute among your will immediately wonder how this will work on a 13,000
pound 32 foot wheel driven boat. The unit will just drive the vane servo
shaft on the Cape Horn steering gear now on order. We could have bought even
a smaller tiller pilot if one was available.

Since I was trying to buy the smallest and cheapest unit I could get, I was
surprised to find out how sophisticated it is. Given the right NMEA input,
it evidently will follow a track to a waypoint instead of just blindly
maintaining a given course. It will even rollover to a new waypoint and run
another leg.

The Raymarine manual describes the inputs needed to follow a track but in
plain English. The Garmin manual for the GPSmap 76Cx I will be using says:

The following are the sentences for NMEA 0183, Version 3.01 output:

Approved sentences-

GPGCA

GPGLL

GPGSA

GPGSV

GPRMB

GPRMC

GPRTE

GPVTG

GPWPL

GPBOD

GPAPB

If anyone could annotate a quoted copy of this list I would appreciate it. I've
tried to find a listing via Google but the only one I can turn up is quickly
replaced by another page before I can read it. Presumably, the Capt'n wants
you to buy the information.

A link to a similar but readable listing would also help.

Any tips or experience interfacing and using one of these autopilots with a
GPS also appreciated.

--
Roger Long