Autopilot R and D - 2011

 What autopilot to get is the question.
 A wheel that will handle our boat or an under cockpit hydrophilic type one.
cptautopilot.com/
As for under deck we have not decide upon a specific brand.
Here is my question out to the forums:



"Hi,

  We are trying to decide on a autopilot. We have an Islander Freeport 36’ sail boat. It weighs in unloaded at 17,000 so a normal wheel pilot will not work.
 So the two options we see are the CPT wheel pilot or under the cockpit sole autopilot.
 One is quite a bit more expensive than the other.

 We will be living aboard and cursing Central America the Pacific coast.

 We would like to install one this summer. We have not yet installed our electronics so we are open to say a Garmin under cockpit wheel pilot that integrates into thee chart plotter.

Now the question, do you actually use the autopilot integrated into the chart plotter?

 I have heard that south of the US the chart plotter is not very accurate so say Charley charts.

 If you do not use them then why would we go to the expense?
People who cross oceans use win vanes and they are not connected to the chart plotter.

Of course we will not be crossing oceans.

 So if we would use the autopilot that is connected to the chart plotter functionality then we would consider it worth it. If not then the CPT Autopilot would probably be our choice.

So any words of wisdom here please?"


Here are some responses:


"Avoid the temptation of connecting an autopilot to a chart plotter! 

Sailing should not be a spectator sport. It is too tempting to lay out a course and simply sit back. Pretty soon your watches will deteriorate into passivity. ("Well, I didn't know we were off course. I thought you had plotted a course to take us through that reef not on to it!") It's a small step from passivity to an abandoned post ("Well, I had to go pee and on the way back got distracted by the movie playing on junior's CD player.")

For our trip from Trinidad to Curacoa due to a software glitch we actually stepped back into the real world and used ...good god I can't believe we still remembered how....paper charts a hand held compass and our GPS.

It was refreshing. Imagine looking around at the world instead of having ones head bowed down contemplating yet another flat plate with the dancing colored pixels.

Of course now that we've solved the software problem.......(fill in the blanks)

Cheers"

Another:


"I switched from a wheel pilot to a below deck autopilot about 10 years ago and couldn't be happier. The old Autohelm (Raymarine ancestor) was very unreliable on my 13,000# 35 footer. Our below deck Raymarine (formerly Raytheon) autopilot uses an electrical drive unit and is coupled to my chartplotter. 

I just replaced all of my electronics (due to a lightning strike) in 2010 with Raymarine gear because the Raytheon stuff worked well and was ultra-reliable.

With just 2 of us, the autopilot has become a third crew member, making the longer trips more relaxing for us. Because it is integrated with the chartplotter, it accommodates set and drift and adjusts the boat's heading to stay on the rhumb line to a waypoint.

By the way, we can enter waypoints directly from the chartplotter instead of picking them off a paper chart and using a calculator to figure out decimal minutes. The 2010 chartplotter allows us to control the autopilot directly, so there is no confusion in setting a waypoint.

Regarding the accuracy of charts, we just returned from the Virgin Islands and carried a portable Garmin chartplotter with the current Eastern Caribbean chart chip. It was rather impressive for its accuracy in reef areas--where it really matters--at least where we were able to verify.

That said, the chartplotters use mapping data from a third party that obtains data from sources that may not be up-to-date. In many cases the mapping data is derived from paper charts that were published before GPS-based mapping was available, so you need to stay alert in unfamiliar waters.

We have also seen mapping errors in local waters that showed up on both Raytheon and Garmin charts, which obviously used the same source for mapping data. BTW, that particular problem was fixed a long time ago. The message here is that the accuracy of electronic charts is probably the same, no matter whose chartplotter you buy. If you buy a chartplotter that uses chips, make sure you have the latest chips. (You should also have recent paper charts, as a hedge on electronic failure.)

Bottom line: We consider an autopilot integrated with a chartplotter to be indispensable for shorthanded cruising. It is a safety feature should one of us be injured underway. Primarily, it is a great convenience that makes for a more relaxing cruise. The helmsperson can eat a sandwich with both hands, for example, and can concentrate on watch duties while the autopilot manages set and drift (if it is coupled to a chartplotter) and otherwise handles the tedium of maintaining your course."


Another from a fellow Freeport owner (our boat type):


"I know what you mean about the reliability of electronic charts outside the U.S., but in those areas outside the U.S. you could lay a route if you had proven waypoints to work with. While it would be a convince to have the autopilot talking to the GPS, I'm not sure if it's all that mandatory. Since someone should always be in the cockpit during the duty watch, it wouldn't be much work to check the course the autopilot is on...no more work than when I check the course of someone else that's steering our boat. That's my take on it.

The only thing I'm not really liking about the autopilots right now, is the rudder angle limitation they have. Right now at low speed I can practically turn the boat on it's keel (turning on a dime), but I'm not sure how tight I could turn with an autopilot...someone else might have some feed back on this.

Don"


Another:


"A wheel mounted autopilot is often times significantly less reliable 
mechanically than a below-deck unit. It provides no redundancy if something in
the steering system fails. Finally, they are often underpowered making for poor
steering performance and increased failure.

As far as connecting the AP to an external GPS/plotter. I've done it and in 12
years of cruising have use the feature three times, all of them when I had a
series of very close waypoints (previously verified by actually traveling over
them) that were so close to each other that I wouldn't have had time to manually
switch from one waypoint to another. One was a 7 mile trip up a very narrow
river with shallow spots, one was the entry into Barra de Navidad in Mexico
where the total route was less than .5 miles and the last was in the Perlas
Islands going through a reef entrance. In all cases, the waypoints had been
recently verified on the water, either by myself or somebody I trusted.


In all other cases, plot a waypoint well offshore and steer a compass course
with the autopilot. That way there's less to fail.

Rick"