[C320-list] Autopilot and instrument upgrade

[Scott Thompson]

I have posted some pictures on the web site of the new autopilot 
installation on my 1999 boat "Surprise." I was looking to replace my 
tired old wheel pilot unit that finally failed with a "Seatalk Error" 
that I couldn't solve last year.

The album can be found here: 
http://www.catalina320.com/mediagallery/album.php?aid=274&page=1.

This is a below-decks autopilot using the Raymarine Type-1 linear drive 
unit. The drive is mounted to the port side of the rudder post on the 
lateral bulkhead that separates the steering gear from the aft cabin. It 
is bolted to a custom mounting plate on the bulkhead, which is 
through-bolted to a backing plate inside the aft cabin, just above the 
internal access hatch for the steering gear compartment. The only part 
of the system that is above deck or exposed to the elements is the P70 
control head at the helm station. The X-10 course computer is mounted 
just outboard of the linear drive on the port side. A rudder reference 
unit is mounted to starboard on another custom bracket attached to the 
corner of the shelf above the fuel tank. The fluxgate compass is mounted 
in the same location as the old one, on a stringer over the center line 
of the bilge, between the galley sink and head door.

Some notes on the installation:

The linear drive drives the rudder through an Edson tiller arm that 
points forward when the wheel is centered. The arm is attached to the 
rudder post just below the main steering quadrant, which is the only 
possible location. There is just barely enough clearance for the tiller 
arm to swing un-obstructed in this location. The installer had 
originally planned to mount the drive on the underside of the swim 
platform, which is a common location for installations on the 350 or 
355. However the swim platform is relatively low on the 320, making that 
arrangement impossible. The selected mounting location on the lateral 
bulkhead seems plenty strong, however, with the added benefit that no 
holes were needed through the deck or hull.

Use of the linear drive requires limiting rudder swing to 35 degrees in 
each direction. To achieve this, some small blocks were added to the 
rudder stops, which are molded into the bottom of the deck just above 
the steering quadrant, for those who didn't know. (I didn't know where 
they were until this project.)

In principle, both the drive unit and rudder reference unit should be 
mounted in exactly the same plane (or a parallel plane) as the tiller 
arm on the rudder. Since the 320 rudder post is not "vertical" (i.e. is 
tilted relative to the bulkhead and other surfaces in the steering 
compartment), in theory the mounting plates and brackets should have 
some compensation for the angle of the rudder post. They do not, but 
everything still seems to work OK. I did not measure, but the linear 
drive appears to be within 5 degrees of the correct plane, which is the 
outside tolerance for mounting per the installation instructions.

Sea trial calibration was very easy. We had to do some big circles to 
swing the compass. Unlike older units, the new system alerts you if you 
are turning too fast or slow. We got maximum deviation of just 4 
degrees, which is excellent. (It is a mystery to me how the computer 
figures this out.) The computer can compensate for up to 15 degrees. 
Then we put the drive in "autolearn" mode. After a few minutes of crazy 
Ivans it was done. The only tweak to drive settings I made was to turn 
down the drive response from 5 (midpoint) to 4 in an effort to cut power 
usage a bit. The unit still works fine on 4. Cutting it further to 3 
caused poor course-keeping, I found.

So how does it work?  Like a charm. The X-10 steers extremely well, even 
with a following sea. No more snake-wake for Surprise. The drive is 
barely audible from the cockpit. I can't hear it at all except when 
sailing in very quiet conditions. It is freaky to watch it steer, since 
it silently makes lots of the same small adjustments I would make. It's 
really nice having the cleaner helm station without the old ST4000 drive 
wheel and motor. I suspect the new system uses somewhat more power than 
the old unit, but that is part of the tradeoff for getting better 
steering, since the rudder is more active than with the old system, 
making more frequent but smaller adjustments. There is very little 
friction in the system, and manual steering is very light with the drive 
in Standby. It's also nice to not have to think about the drive clutch 
when I switch between Standby and Auto, since that is completely automatic.

I do have a few minor complaints. As previously mentioned, I had to give 
up a bit of rudder swing. That doesn't seem to be much of an issue so 
far. The P70 control head has a general purpose color backlit LCD 
display with all kinds of display customization and bells and whistles 
possible. However it doesn't have as much contrast as the older units, 
especially with sunglasses, and I need to keep the brightness set to 
100% in sunshine. The "graphical" display mode on the P70 does not match 
the pictures in the manual, and is an extremely distracting and lame 
"rolling road" animated graphic. A lot of this doesn't matter since the 
new e95 MFD chartplotter that I installed at the same time is highly 
customizable to show whatever you might want.

We also replaced the speed, wind, and depth instruments and transducers 
at the same time, added an external GPS antenna, and the previously 
mentioned e95 chartplotter, all from Raymarine. (Raymarine is running a 
promotion where I will receive an i70 multifunction display for "free" 
since I purchased the e95. I don't know what I will do with that.) In 
general the new instruments are similar to the old ST60 ones that they 
replaced.

The e95 is my first chartplotter. Previously I used a hand-held Garmin 
GPS76 unit on a bicycle handlebar mount above the instruments, with a 
data/power cable interfaced to the autopilot through a connector I 
installed on the back of the Navpod. This system worked very well, 
albeit without the fancy graphical displays, and with no chart 
information. But it used almost no power and was a familiar and easy to 
use friend that worked well with the Raymarine pilot through the NMEA 
interface. The e95 is highly customizable and will show you almost 
anything you can think of with the right inputs and enough 
configuration. It is bright, colorful (and power hungry) and comes with 
a 300 page pdf manual that I am still trying to work through. I'm still 
getting used to it and hope it will become as second nature to use as my 
ancient Garmin. However I have a few complaints about it. It sounds a 
VERY loud and annoying waypoint arrival alarm when I am still a good 
distance from a waypoint. If I push "track" to accept the new course 
(and to silence the alarm) it IMMEDIATELY turns the ship in the 
direction of the new waypoint rather than waiting until I actually reach 
the old waypoint. On several occasions this caused me to almost run into 
large buoys or fixed markers, or to turn inside of them instead of 
passing on the required side. Fortunately the Standby button is easy to 
reach. Hopefully I can find some parameters to tweak so that the 
chartplotter gives more reasonable course change instructions to the 
autopilot. And why can't they implement an alarm that gives some warning 
before arrival, but doesn't sound like a fire alarm until you actually 
get there? I'm also annoyed that the new unit has no tide/current info 
unless I upgrade to "Gold" or "Platinum" Navionics charts at a high 
price. And the Voyage Planner software is an extra $49 on top of the 
$$$$ for the chartplotter, but is totally brain dead. However it's the 
only tool I've found for transferring waypoint or route information 
to/from the unit because Raymarine insists on using a proprietary file 
format. Seems to me that the included software for the fishfinder, 
radar, AIS, weather data, infrared camera, XM/Sirius radio, and 
Raymarine proprietary sound system (none of which I have) should be 
priced extra rather than the simple and buggy waypoint transfer software.

Finally, we swapped out the VHF for a new ICOM model with remote mic at 
the helm.  I finally have DSC and a working distress alert system.

Kudos to Phil and his team at Electronic Marine in Annapolis who did 
beautiful work installing all of the above on a tight schedule.