On Morgan’s Cloud we don’t hand steer much: approaching and leaving a wharf, anchoring and hauling the anchor, transiting an intricate channel, or in the presence of a lot of other boat traffic; that’s about it. We find that by using our autopilot we are left with more time and focus to navigate, keep a good lookout, and sail the boat. We also find that having a plotter has the same benefits.
But we don’t have the two electronic wonders interfaced to allow the plotter to instruct the autopilot on what course it should steer; we do that manually. Here’s why:
Changing Course Keeps Us Thinking
The manual step of changing course at each waypoint reminds us to make sure that the next leg of our route is well clear of any obstructions as well as making us think about and look for any dangers that did not exist when we laid out the route originally. For example, a change in wind direction and strength that puts the next leg closer than is prudent to a lee shore.
Manually Adjusting Our Course Keeps Us Aware
Once on the new course, the requirement to monitor the cross track error makes us immediately aware if a current is setting us to either side of the desired course, always good for our general situation awareness. Keeps us awake too.
Following Cross Track Error Is Often Slow
Further, the presence of a current does not mean we slavishly adjust to minimize cross track error, as an autopilot being driven by a plotter would, since there are many situations where this will result in a slower (sometimes much slower) passage.
For example, when crossing the Gulf of Maine from Nova Scotia to Maine, we set a course directly for our desired landfall and let the current take us off course, first one way and then back the other, as the tide changes. This is much faster than fighting the current, first one way and then the other, to stay on the rhumb line.
A Potential Accident
One lovely moonlit night a couple of weeks ago we were sailing offshore on a broad reach in company with another boat to leeward. Phyllis, who was on watch, was amazed to see the other boat suddenly luff up violently, tack, continue the circle to jibe all standing, and then go on behaving erratically for a minute or so before settling down to her original course.
Later, we learned from the other boat’s crew that they had been changing some settings on their plotter when they inadvertently chose the wrong option from the plethora of menus that these machines display. The plotter that was driving the autopilot at the time produced the violent changes of course as the crew struggled to get back to the page on the plotter that would let them disable what was by then an electronic rogue.
I suspect that the crew could have quickly taken over and hand steered by just hitting the standby button on the Autopilot, just as you would do if the plotter and autopilot were not interfaced and the autopilot went nuts. But the fact is, they did not do that. This is the second time in just a couple of weeks where we have seen overreliance on plotters cause problems because the crew were distracted by them.
Thinking about the menu of potential disasters while the boat was out of control and the crew distracted is sobering: hitting us, damage from a crash jibe, a crew injured or knocked overboard in the melee, to name just a few possibilities.
Summary
So while many sailors that we respect have their plotters and autopilots interfaced, as detailed in this comment that inspired this post, we will not go that route on Morgan’s Cloud.
What do you think, interfaced, or not? Please leave a comment.
Further Reading
- Anatomy of an accident, another plotter induced problem.
- More articles on electronics
- Articles on navigation and situation awareness
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Chris December 18, 2010 at 6:24 pm
There is no electronic or electro-mechanic technology that frees one from the responsibilities of command.
It is entirely possible to do irresponsible things with and without technology.
Therefore, interfacing competently designed, and manufactured equipment is no more or less risky–provided–one adjusts one’s command behaviors to the situation.
We use our interfaced system as a an extra, but not able-bodied, hand. We don’t treat the autopilot as officer of the deck, that is us.
We are, however, routinely nearly rundown by power and sail boats that code in a string of way-points and then go off to do who knows what perhaps with the presumption god is their pilot.
If there is a problem with any of these technologies it stems from the enabling of the in-able. A competent sailor should be able to interface with confidence and not to when conditions make it inappropriate.
David Nutt December 19, 2010 at 8:58 am
On Danza we do have our GPS and autopilot linked and it has worked well for us in the last 50,000 miles of sailing. Like John and Phyllis we let the autopilot do 90% of the steering but we cold and shivering humans do 100% of the watch standing. This includes monitoring the track on the computer screen, the heading, the course steered and all the little bits and pieces of data obtained from this and everything else that consumes life at sea. Assumption is the mother of all screw-ups.
John December 20, 2010 at 7:43 pm
Hi David,
I love the last line. Ain’t it the truth.
Robert in Norway December 19, 2010 at 9:05 am
I have never had either a plotter or a pilot on any of my boats and never will. Paper charts and a Monitor vane cover all my needs and are fail proof. These boxes are expensive toys and dangerous when used by newbies. The pilot is an especially unnecessary bit of kit and having it onboard implies large batteries, charging systems and complexities involving the steering of the boat. If your boat is motoring in a calm, some one should be on the helm. The expense of of these toys does not help to make cruising “attainable”.
Scott Kuhner December 19, 2010 at 12:58 pm
Robert, did you know that you can set up your Monitor so that a small tiller pilot like the Raymarine 1000 will drive the wind vane? We use this method when we are sailing along a coast and want to steer a compass course, not a wind course.
Victor Raymond December 19, 2010 at 9:43 am
John,
As an aircraft pilot flying single pilot, we almost have to have the autopilot on and our navigation system driving the AP. They don’t call them Flight Management Systems for nothing. But there is a fairly large red button on the yoke of every modern aircraft that is FAA required to disconnect the AP just in case.
Boats on the other hand are very slow moving vessels for the most part. I agree with you and have never felt the need or the comfort in having the AP steered by the chart plotter route. In addition I have multiple redundancy with electronic charts available on my iPad, Garmin 496 and sometimes my trusty old MacBook. I have found different charts have slightly different information and I can compare them with what the eyes are seeing. While I do think having and using an AP is like having another trusted and faithful crew member, I do think having and using a wind vane system is a good idea too. It is on my list for the next boat.
Scott Kuhner December 19, 2010 at 12:55 pm
John,
Great article. Thought you would laugh at a recent incident we experienced re chart plotters.
Tamure is at a dock in Jupiter Fl; but, we recently drove to Ft Lauderdale to have dinner with Steve and Karen James (whose boat is in the Med), David Bridges (who has sailed his Valiant 40, Blue Yonder across the Pacific) and his girl friend Marty, and Pam Wall, who has also sailed around the world with her late husband and their kids. While we were at the dinner table, Steve mentioned something about a new chart plotter and suggested I get one. I said that I don’t use one and don’t need it. “But”, he said, “The one I am talking about is only $600 and that includes all the charts of the US east coast.” I said, “Steve, we have sailed around the world twice, once with only a sextant, and the second time with a Sat Nav that would give me a position once every six hours or so. I am very vigilant in my navigation and besides, there have been more cruisers who have gone aground using a chart plotter than in the days when there was only the sextant. I do not need one!” Steve then came back with, “Scott, you should have one because they are very useful especially in situations where visibility is limited and where you aren’t sure where to go.” I said firmly, “Steve, I don’t want one! I am a very competent navigator and I don’t need one!” With that David reached into his pocket and pulled out his I-phone. He pushed a couple of buttons and showed it to Steve, who immediately broke out laughing. Then he pointed the I-phone at me and there was a picture David had taken of Tow Boat US pulling us off the sand bar at the entrance to Adams Creek. Touché!!
John December 20, 2010 at 1:27 pm
Hi Scott,
Great story. Don’t you hate it when they have pictures?
Steve Dashew December 19, 2010 at 1:11 pm
Howdy John and Phyllis:
We are back in Az and just read and agree with your piece on plotters and pilots. However, there are two situations where having the autopilot follow a track could be helpful. One is in an MOB situation. The other is if you have worked your way through an intricate channel and need to exit in less than ideal visibility, say an atoll in the S Pacific. That said, we do not have ours connected, but have thought about it because of these two scenarios.
After five days in the house I am ready to return to the boat!
Regards – Steve Dashew
John December 20, 2010 at 1:18 pm
Hi Steve,
A really good point on those two scenarios. The first point might even get us to interface the two, just for use in a MOB situation.
One thought on using the plotter outbound to follow your own inbound course:
Three weeks ago we were exiting the intricate channel that runs from Beaufort, NC, to Beaufort Inlet and I noticed, to my surprise, that our inbound course line on the plotter ran outside the channel and over a mud bank!
I have seen this plenty of times in Greenland or Newfoundland where the datums are out. In this case following the incoming track would keep you in deep water.
But in the Beaufort case the track was in fact outside the channel, and not by a little. I can only assume that the GPS or the plotter were off for a few minutes while we were entering the channel. (We would not have noticed as we were dealing with a lot of small fishing boats and navigating by the marks.)
Just another time where blindly following the plotter would result in a grounding.
Chris December 20, 2010 at 2:53 pm
John, you might want to look a little deeper at this. Five times and places on our last coastal US trip, we had the GPS track crossing either over or through unpassable areas (such as docks and bridges). We carry a GPS constellation and signal health monitor in our equipment suite and there were no performance issues with the constellation. [It uses statistical process control to detect and report worrisome position dilution and timing issues/trends.]
I was about to talk to the digital chart provider when I decided to download and print NOS charts for the area to see what was what.
In four of the five cases, the NOS Charts were wrong.
In two of the four, the docks were mislocated on the NOS chart by 10-12 meters– this was checked by comparing satellite photo measurements with chart measurements (both absolute and relative in case scaling was an issue).
In one of the four, the State did not build the bridge where it received federal approval to build the bridge and the NOS position was based on the federal approval drawings. Not only was the bridge deck 40 meters out of position, so were the approach ramps, etc for a mile either side of the channel. The mis-location was obvious on radar.
Finally the fourth spot was between Beaufort Inlet and Beaufort. The recorded trace from our depth finder showed us in more water than we needed and much less water than a spring tide lower low offered according to the chart. We altered course to the west to get out of the cresting swell this depth anomaly caused.
So let’s compare four piloting cases.
One, I’m electronics free and hand or windvane following a compass course laid in by plotting on a paper chart. The depth in Beaufort won’t be right.
Two, I have a full suite of electronics, not connected to one another, and I am hand/vane steering to a course laid in from a paper chart (ok, it’s null difference).
Three, I have a full suite, they are interfaced and auto steering to a compass course–same result.
Four, I have a full suite, they are interfaced, and I am auto-sailing to a waypoint on a digital chart that accurately represents an incorrect paper chart–same result.
While I very much respect the views presented here, as I noted in my first comment, the issue here seems to me to be about the inherent risks of sailing and the level of mental involvement on the part of the crew. If interfacing causes one to go brain dead, I would suggest avoiding it. If interfacing reduces fatigue and allows one to expand and extend one’s situation awareness as a result, I would recommend it.
We interface our equipment, and we allow the AP to use waypoint positions when it is navigationally appropriate, we don’t when it isn’t. We use course and heading inputs when waypoints aren’t appropriate. To us, this seems better than “never” and “always”–two answers my teachers often suggested would not improve my grades.
John December 20, 2010 at 7:20 pm
Hi Chris,
Thanks for your interesting and complete comment. Just to clarify, I think that I am right in saying that the errors you are talking about are datum and chart errors. The error we experienced was a repeatability error, a completely different thing.
Chris December 20, 2010 at 8:02 pm
Aha, indeed it was. And as I said, I respect other’s choices, but having been rundown by a single hander who abjured integrated electronics, and was asleep from fatigue when he hit us, I remain convinced we are talking flavors of risk here.
Dick T M/V Julia Bryant December 19, 2010 at 2:53 pm
John:
Right on- the non-interconnection of AP and Plotter. My personal technique (or lack of technique) is to slavishly use the course projection line on my Raymarine E Series in coastwise navigation. You can simply set the boat’s courseline projected to your next Waypoint, engage the AP but don’t interconnect. Granted this is a 12 Knot motorboat cruising where crosstrack error etc is less critical. Since there are two projections – one compass and one actual, you can soon figure out what’s happening crosstrack-wise. I have no idea whether most chartplotters can enable course projection lines, but would think so. Re: a previous comment on $ 600 backup plotters, my current one (for next season anyway) is my Droid X Motorola device with Navionics Eastcoast charts loaded for I think 13 bucks. Same would go for the IPhone. Of course this supposes you’re in range of Verizon’s 3G signal. I met recently an offshore fisherman at the New Bedford MA Verizon store and I asked him what sort of range he got with his cellphone. He said routinely when returning from Georges Bank, 40 miles out he climbs the radar mast and gets cell service to New Bedford.
John December 20, 2010 at 1:25 pm
Hi Dick,
Good point on the course projection line. This is a feature we really like on our plotter and use all the time since it helps our situation awareness by graphically showing where we will be in 6 minutes (the period we have ours set for). Also, if it diverges a lot from our heading, it is an immediate indication of a cross current.
I have to say that I’m not very happy about this trend to use phones and tablets as navigation devices, even as a backup. I may be old fashioned (may?) but I would prefer a purpose built hand held GPS and a paper chart as backup.
richard December 19, 2010 at 5:31 pm
interesting comments…many are along the lines of the radar topic of a few months back (my comment then was that radar tends to suppress our natural nautical instincts that we have worked so diligently to cultivate so i purposely do without it)…far be it from me to take issue with steve dashew; however, in all my many thousands of hours waterborne (still not in steve’s league) including blue water passaging, i have never even been close to any mob situation and my enounters with limited visibility are nearly as rare as i have a tendency to stay put if this is a threat….still steve’s opinions are extremely valuable…always happy to glean from his knowledge and skills….richard based in tampa bay…cavu’s skipper
Bob Tetrault December 19, 2010 at 7:15 pm
Hi John, Phyllis, right on! No interface on anything I own. Too easy to leave the watch for something unrelated to Navigation or safety. The only proper course change is a manual one. When I hear of others practicing unsafe navigation I wonder how long before we bow to rules and regulations aimed at keeping us from running into each other and the ground? My navigation instructor would roll over in his grave if he thought I adopted such practices. Bob Tetrault MMA 73D Retired merchant marine deck officer. S/V Sea Return
John December 20, 2010 at 7:38 pm
Hi all,
Thanks for the great comments. Lots of very interesting and well expressed points of view.
While I would stick with our base position that it is safer not to let the plotter drive the autopilot, I think a key issue emerges here and that is:
It is perfectly safe for an experienced navigator and mariner like David Nutt–I single him out because I know him–to let his plotter drive his AP because he has the experience to know when to break the connection and what the intrinsic hazards are.
However, I think there is a real danger induced when someone new to our sport who has never learned basic navigation and piloting skills does the same thing.
A metaphor might be a pilot who flew a plane fitted with one of the new automated landing systems that I believe will fly the plane all the way to final flare just before landing (correct me if I’m wrong about this, Victor).
For an experienced pilot in a raging snow storm, such a system enhances safety. But for a new pilot who has never learned to land manually it would be a crutch that would stop him/her understanding his/her surroundings or learning basic flying survival skills.
In summary, perhaps something all of us more experienced sailors can agree on is to do everything we can to encourage those coming into the sport of offshore voyaging to get proper training and experience in basic navigation and pilotage skills and to mentor those people whenever the opportunity arises?
Steve Yoder December 27, 2010 at 11:40 am
The pilot and plotter are not integrated on Sempre Sabado either. I just don’t like the idea. Another small advantage, besides all of those already listed is that, when I’m laying out a course prior to a trip, I set up waypoints where they look like they should be on the chart. However, when I get out in the real world, I often save some time when changing course by “rounding out” the turns instead of sailing all the way to my waypoint and then making an abrupt course change when reaching the actual waypoint that I plotted. This “rounding” could take another 4 or 5 waypoints per course change if I actually plotted the course that way. These adjustments are easy to make when the pilot is just doing what I tell it to rather than what the plotter is telling it to.
John December 28, 2010 at 2:16 pm
Hi Steve,
A really good point. We do that all the time. We tend to be very conservative about getting close to dangers when setting the route out in the plotter prior to starting the passage. But when we can actually see our surroundings it is often possible to shorten the route a great deal without being fool hardy.
Marc Dacey April 1, 2013 at 3:32 pm
Sometimes an older post here will be revealed through a fresh comment made on it, and that once again illustrates for me how parallel our thinking is.
This is a screed I wrote somewhat critical of “integration” back in 2011:
http://alchemy2009.blogspot.ca/2011/10/plea-for-segregation-over-integrationat.html
I can’t say things have improved much, nor are people warming to my points of view.