How is auto-pilot used?

[Shrew]

Originally Posted by dhays

It takes me 15 seconds to leave the PH, go to the galley, grab a water from the fridge, and be back in the PH. And that is for a middle-age guy with two bad knees. That means that at my typical 7 knot cruise speed I have traveled much less than 1 boat length. I can make a cup of coffee in my Keurig in about 3 boat lengths (although I don't. I start the cup of coffee, go back to the PH and then go retrieve the coffee after it is finished so I am away from the helm for 2 boat lengths at one time and 1 boat length to retrieve the cup later.)

7kts = 11.8 ft per second. 11.8 x 15 = 177 ft.

I suspect 7 kts is moving farther than you think it is.

[dhays]

Originally Posted by ulysses

Wow how long is your boat ? I did the math and it must be over 170 feet.

I could easily have failed in my math. Yup, looks like I was off by a large factor.

Quick estimate, about 6,000 ft per nautical mile. 7 knots would be 42,000 ft. 15 seconds at 7 knots would be 175ft or about 4 boat lengths?

See what happens when I try to do mental math before my second cup of coffee!

[Britannia]

I find an autopilot invaluable for the reasons everyone has given. Like many of you, I will make a short trip to the galley at cruising speed, but a trip to the head is done at idle.

I used to have gps/route following autopilot on my sailboat. My current autopilot is capable but not wired for it. The big advantage of this feature in my experience is the ability to stay on the intended track. If I'm navigating through an unfamiliar area I will plot out a course and inspect the whole route at various levels of zoom on my charting software. In this way I build confidence that there are no hidden hazards in advance. This doesn't obviate the need to stay alert, but it does provide a safety net - if I'm on track then I know I have already checked that it's "safe." This is the approach I took coming back from Alaska.

To appropriate a well know axiom "the shortest route between to points passes through a buoy!"

Richard

[schrater]

We always maintain an adequate watch, but I prefer to steer with autopilot in all but the most dynamic situations. The AP holds a more consistent course with more gradual adjustments than I can. I actually think it helps me be a better watch, because I feel more free to really move and look all around. And if my heading is off by a tick or two, I can just nudge it over.

[Lepke]

Autopilots are like having an extra person on the boat. It relieves the tedious steering. In the ocean, away from other vessels, it is possible to leave the wheelhouse for very short periods. But international/national law requires a present deck watch. In restricted waters, especially with other boats around it is dangerous to leave the wheelhouse.
That said, I use my autopilot all the time, everywhere it is possible. I hate steering having done 100s of hours. But I keep watch and am prepared to take the wheel.

[BandB]

Originally Posted by Lepke

Autopilots are like having an extra person on the boat. It relieves the tedious steering. In the ocean, away from other vessels, it is possible to leave the wheelhouse for very short periods. But international/national law requires a present deck watch. In restricted waters, especially with other boats around it is dangerous to leave the wheelhouse.
That said, I use my autopilot all the time, everywhere it is possible. I hate steering having done 100s of hours. But I keep watch and am prepared to take the wheel.

We always steered on the lake, many house, many days. If you told me on the day I was planning to cruise 10 hours that the autopilot was broken, I'd probably decide just to stay and have someone fix it, go tomorrow. I can't imagine right now steering manually for 10 hours.

[C lectric]

When our A/P worked I often was alone on the boat. For coffee I would leave the wheel but since the coffee on the stove was two steps away and I could still see out and all around just fine there was never a problem. Only done after checking there were no other boats nearby.


If I had to go to to the head I killed the throttle into neutral. I didn't a couple of times and even at idle I was surprised how far the boat had travelled. Even though there were no boats about there is often lots of big wood and often prawn trap floats which can be troublesome.

Of course when my wife was aboard she would keep lookout so the boat could be allowed to continue. In heavy traffic areas/times I would hand steer.

[Conall63]

Originally Posted by BandB

We always steered on the lake, many house, many days. If you told me on the day I was planning to cruise 10 hours that the autopilot was broken, I'd probably decide just to stay and have someone fix it, go tomorrow. I can't imagine right now steering manually for 10 hours.

I'm now a member of that church.

Conall

[rjwilliams11741]

Originally Posted by RT Firefly

Greetings,
Mr. j. As Mr. mr posted, you are required, by law, to keep a constant watch while the AP does the steering (speed is set by throttle) on a programmed or set course. Our AP (Wood-Freeman 500) holds one set course only and cannot be programmed or interfaced with other electronic devices like more modern units can.
The more modern units can be programmed to change course at pre-set waypoints and take you from point A to point B without touching the helm but I have no experience with these. Wish I did.

Wow, you still use a Wood-Freeman 500. I had one on Freedom that lasted 35 years with no real trouble. They actually supported them until about 5 years ago. It finally died and I replaced it with a popular brand AP. That one lasted 3 years before I had to replace the "brain". The new one is great in that I can program it for a continuous series of courses but the WF was certainly bullet proof.

[Maerin]

Originally Posted by menzies

Just an update on the above. AP will take a route (multiple waypoints) from a GPS and follow the route - however I believe that no AP will make the next turn for you. It will notify you when it is time to accept the next waypoint but, in case there are reasons the turn should not be made, it will not do it for you. That is certainly the case with my dual set up.

To clarify, an AP won't use multiple waypoints. It steers to one waypoint, and that is only a virtual waypoint. In reality, the chartplotter sends a bearing to the AP for it to steer, sends cross track error,(how far off in distance the vessel's current position is from the rhumb line that the chartplotter has determined from current position to the active waypoint), direction to steer (L/R), lat/lon, active waypoint ID and some other data depending on the chartplotter. The AP may receive the lat/lon, speed, or other data but it may not necessarily do anything with that data. The AP has an electronic compass or input from one, that it uses to determine heading, it typically sends that data to the chartplotter. Each AP uses slightly different variations but most are of similar function.

Simrad will make waypoint course changes contingent on a configured setting, typically a course change of less than 30 deg will be made without user intervention. Raymarine OTOH requires acknowledgement for each waypoint course change.

The reason a chartplotter using a route or even a single active waypoint is more accurate is that it continually adjusts the data sent to the AP to compensate for set and drift, something the AP is incapable of. Sure, the AP will steer a compass course, but it's a dumb setting, e.g. it maintains the heading, it just doesn't know where it leads to, so it can stay on the correct heading but end up way off the mark.

It's simply astounding how many cruisers are intimidated by the chartplotter/AP interface to the extent they won't utilize it; even more so how, when they finally get over the hump in the learning curve, they wonder why they didn't do it sooner!

[Acheron2010]

Don't be this guy.

[AusCan]

I have also become very dependant on my autopilot. I'd estimate that the A/P would be on >95% of the time when the boat is underway. I even keep a complete 2nd hand spare unit on the boat to change out if the original ever fails.

Since we almost alway boat in clean open water, there is very little traffic or flotsam to require a change in direction, so hand steering does get a bit old. The A/P allows me to use the head or cook lunch while cruising singlehanded. I often cruise all day without seeing another boat once I'm away from the marina.

My wife and I enjoy lazing in bean bag chairs on the foredeck with the A/P remote at hand if ever required.
I also find the A/P very handy for keeping the boat pointed into the wind when raising or lowering sails singlehanded.

[MYTraveler]

Originally Posted by menzies

Just an update on the above. AP will take a route (multiple waypoints) from a GPS and follow the route - however I believe that no AP will make the next turn for you. It will notify you when it is time to accept the next waypoint but, in case there are reasons the turn should not be made, it will not do it for you. That is certainly the case with my dual set up.

My Simrad will make the change if it is less than something like 15 degrees.

[MYTraveler]

Originally Posted by Acheron2010

Don't be this guy.

Although my AP is on 95%+ of the time when the boat under way and out of the harbor, I never set a way point that has an island behind it.

[MYTraveler]

Originally Posted by Maerin

To clarify, an AP won't use multiple waypoints.

Correct, although the difference is technical and not functionally different. Some AP's (including Simrad) will steer a course (with course changes on their own). Those courses can be to follow bottom contour, zig-zag, box, etc., or even return to MOB.

[MYTraveler]

Originally Posted by Lepke

Autopilots are like having an extra person on the boat.

That's why some people refer to a fictitious crew member as "Otto".

[hmason]

I plot my course for the day on my chartplotter, engage the autopilot to follow the route. Then I go below and go to sleep until the arrival alarm goes off or I get hungry. 10 hour runs are easy that way.

[hjorgan]

Love our Raymarine AP (Captain Ray). We have a fast mover, and Captain Ray can handle steering at 4 or 40 knots. At trolling speeds Capt. Ray is indeed an extra hand, allowing me to help anglers, clear lines, and use the radar and sonar more effectively.

I'll have an AP, a windlass, and radar on any boat I fish. Sat TV is optional!

[North Baltic sea]

Originally Posted by BandB

95% + of all our boating is done with an Autopilot. However, we never leave one unattended or with no one on watch. That includes stepping below for a snack or to use the restroom or any other reason. If we need to take a break we have someone else take over and if there isn't someone else available, then we stop or idle long enough to do whatever we need to do. We don't continue at speed while not on watch. I know that's probably very much a minority view here of zero tolerance but when you create a grey area it seems to just keep expanding.

I think you are 100% right, because international sea rules oblige you to look and move at speed, and you can stop, dodge, or set the gear back when you need it.

I think AP is one of the most important equipment on the boat, I once had a boat where it was not and for example in the mist driving without the AP it is a nightmare to stay on course with just a compass and chartplotter in the archipelago narrow coves in rocky waters. For some reason I leave the ship to get out of the starboard when you keep looking, watch the course compass and still look at the radar / map screen.

BandB i appreciate your attitude, it's a good seamanship!

Others to read the rules of the sea 5 & 6 link to rules
http://www.google.fi/url?sa=t&rct=j&...AEhDvwPFqZPVrw

[markpierce]

Otto is my primary helmsman. I'm primarily lookout and navigator.