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Author Topic:   Auto-Pilot
jimh posted 05-05-2011 10:43 PM ET (US)   Profile for jimh   Send Email to jimh  
I have been looking into an auto-pilot, and from what I have found it appears that the least expensive of these devices will cost $3,000. Have I overlooked something less expensive?

I am looking for an auto-pilot that will hook into my hydraulic steering system, and will operate independently of other electronics like a chart plotter and GPS receiver.

Making me even more miserable is the notion that my current hydraulic steering might not be compatible. I have a side-mount actuator cylinder which is asymmetrical--that is it takes more turns in one direction than the other to move the engine from limit to limit. This type of cylinder is often noted as not being compatible with auto-pilot systems. Replacing this cylinder will add another $500 (or more) to the cost of an auto-pilot. Am I correct that the side-mount cylinder will have to go?

Jefecinco posted 05-06-2011 09:57 AM ET (US)     Profile for Jefecinco  Send Email to Jefecinco     
I know absolutely nothing about auto-pilots(AP), sorry. If the cost for a small boat AP is approaching $3500 even when not configured with a GPS that is a real luxury given that it will only follow a straight course. I remember a few years ago that a low cost AP that simply attached to the boat's steering wheel was marketed. I don't know if it was much good, or not, but I have not seen one advertised for a good long while.

A friend who routinely runs 30 miles offshore to fish on specific reefs has a locking device on his steering wheel. He sets a course, locks the wheel, and enjoys the ride while making occasional reference to the GPS and small corrections to the course. His GPS is set to alarm at a certain proximity to his destination and when it sounds he unlocks the steering and takes control. His cost is probably under $50.


Tom W Clark posted 05-06-2011 11:47 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Yes, in general you must have a balanced steering cylinder when using a hydraulic autopilot, though I note that Garmin offers an "Unbalanced Steering Cylinder Valve Kit" part # GMN 010-11201-00 for an extra $88 from one source: aspx?iid=GMN%20010-11201-00&cid=160601&bid=442

For considerably less money, perhapas as little as $1500, you can buy the venerable old Si-Tex SP-70 Autopilot. This autopilot makes use of your hydraulic steering hoses by taping into them with TEEs. You need to mount the pump, fluxgate compass and controller head in dry locations.

I have a Si-Tex SP-70 in my Revenge Walk-Through that was installed in the 1990s. It is still performing flawlessly.

The Si-Tex SP-70 is actually a ComNav product, their ComNav 1440 which is sold everywhere except North America. ComNav is a well regarded Canadian company in Richmond, British Columbia.

jimh posted 05-06-2011 09:30 PM ET (US)     Profile for jimh  Send Email to jimh     
Thanks for the information on the Si-Tex or ComNav auto-pilot. If it is from the 1990's I would agree with the description of "venerable," but if it works, it works.
jimh posted 05-07-2011 09:05 AM ET (US)     Profile for jimh  Send Email to jimh     
I obtained the installation manual for the ComNav 1440 autopilot from their website. (This is the same device as Si-Tex markets as the SP-70 in North America, apparently in some sort of re-branded marketing arrangement with ComNav.) The URL for the document is

On page 30 of the manual, under the subheading Hydraulic Connections for Two Line Steering Systems, there is an illustration that shows the method of connecting the auto-pilot's pump. Although this diagram is for "two-line" systems, it shows a third line, labeled as a compensating line that interconnects the helm pump and the auto-pilot pump.

From the text that follows the illustrations, this third line is also referred to as a bleed line and flows into the reservoir of the helm pump. There are also specific requirements for the orientation of the bleed line with respect to its elevation relative to the two pumps.

Is the addition of a third line (called a compensating or bleed line) typical with all hydraulic steering systems with an auto-pilot?

acseatsri posted 05-08-2011 02:57 PM ET (US)     Profile for acseatsri  Send Email to acseatsri     
Did you look at [the RAYMARINE S1000] for $1,000?
jimh posted 05-08-2011 05:07 PM ET (US)     Profile for jimh  Send Email to jimh     
I obtained the installation manual for the RAYMARINE S1000 auto-pilot and reviewed installation procedure for the S1000. This auto-pilot also requires a third hydraulic line be installed between the helm pump and the auto-pilot's electrically operated pump. Based on this it seems reasonable to conclude that all of these auto-pilot hydraulic connections to the helm pump will need a third line installed.
jimh posted 05-08-2011 05:15 PM ET (US)     Profile for jimh  Send Email to jimh     
The RAYMARINE S1000 auto-pilot does not employ a rudder position sensor, while the ComNav 1440 (or Si-Tex SP-70) does require a rudder position sensor. For installation on an outboard engine, a rudder position sensor will likely require a link to the steering arm or tiller of the outboard engine. This makes the installation a bit more complicated. On this basis I would tend to favor the method used by the RAYMARINE S1000, which appears to not need the rudder position sensor.
Tom W Clark posted 05-08-2011 09:24 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Yes, my autopilot uses the third hydraulic line as described. It is fit the upper most tap on the back of my original SeaStar I helm.

Yes, my autopilot uses a linear rudder feedback unit which many current autopilots do not. This is one of the weaknesses of my autopilot; the rudder feedback unit is strapped to the steering cylinder and is thus exposed to the elements in the splashwell. I have had to replace it once (it was very expensive). It also adds clutter to the rigging back there.

However, based on anecdotal reports, I have concluded that autopilots with an actual rudder feedback device steer a more true course, especially at slower speeds. Top-of-the-line autopilots from manufacturers like FURUNO use rudder feedback units with their autopilots.

I should note that the Si-Tex SP-70 does not come with the fluxgate compass included. I have one but it an extra cost option. That may make the Si-Tex unit less competitive.

I am very surprised at the low cost of the Raymarine S1000, as low as $930. How does it differ from the Raymarine ST70 SmartPilot X-10, which costs closer to $2500? I suspect we are not comparing apples to apples.

jimh posted 05-08-2011 09:59 PM ET (US)     Profile for jimh  Send Email to jimh     
Tom--Thanks for the comments on the third line in the hydraulic system.

It seems like many of the newer auto-pilots do not require a rudder position sensor, but on some of them it is an option. Usually options improve performance, so perhaps having a rudder position indicator will generally improve auto-pilot performance. The units without a rudder position indicator must try to keep track of how much rudder input they have applied by gauging how long they have let the pump run.

The S1000 appears to keep costs down by omitting the fancy control head, which typically costs about $700 all by itself. The hydraulic pump also seems to be small and perhaps its output capacity is limited compared to the more expensive models which can be used on larger boats.

At a $1,100 price point an auto-pilot could be an option for me. However, there is the matter of the unbalanced cylinder I currently have, and that would have to be replaced first. My hydraulic cables have no slack at all, so I would need to replace them, too. At that point, heck, I might as well get a new helm pump and update the whole system! Now we are talking some real money. This project may stay at the kitchen table stage for a while.

Guts posted 05-24-2011 07:05 AM ET (US)     Profile for Guts  Send Email to Guts     
I'm using a Simrad autopilot on my Montauk 17. it has an auto feedback attached to the outboard which I've never had a problem with all in all I'm very happy with the autopilot.
Ferdinando posted 06-01-2011 04:39 PM ET (US)     Profile for Ferdinando  Send Email to Ferdinando     
Just finished installing the Raymarine 1000 on my 190. Works perfectly, easy to install and so far I'm really happy with it.

For $940 bucks I can't complain, although I did have to spend $900 for the Seastar Hyd steering, but it was well worth it.

David1877 posted 06-07-2011 11:38 PM ET (US)     Profile for David1877  Send Email to David1877     
I have the S1000. Overall I have been happy with the performance. Once in awhile it will lose the course from the gps but this is not frequent.

I have the Eastport 205 and troll at low speeds.

20dauntless posted 07-10-2011 06:41 PM ET (US)     Profile for 20dauntless    
Hi Jim--I just purchased a Raymarine S1000 for $910. My local installer will charge me about $330 for installation, so my total installed cost should be under $1,300.

I have a single engine and a Sea Star hydraulic steering system. The Autopilot will be networked into my Raymarine C80, but it can work independently. I've heard that the S1000 is not a great choice for fisherman, but for cruisers like me it apparently works well and was much cheaper than the options from Simrad, Furuno, and Garmin.

It should be installed in the next several weeks. I can report back on performance if you'd like.

jimh posted 07-11-2011 08:11 AM ET (US)     Profile for jimh  Send Email to jimh     
Do let us know how the S1000 Auto Pilot works for you. Thank you.
20dauntless posted 09-19-2011 09:45 PM ET (US)     Profile for 20dauntless    
Jim, I just got back from a month long trip to South America and got a chance to take the boat out and try out the Raymarine S1000.

In short, it works great. I can easily navigate routes (the AP beeps and requires me to acknowledge that it needs to turn before initiating a turn at a waypoint), click on a location on the chart on my MFD (Raymarine C80) and navigate there, or simply press a button and have the autopilot maintain the current heading.

I haven't tried it in any rough water yet, but it did great in calm water, even at dead slow, which in my boat is about 2 knots. So far it is a great addition to my boat and it will make long days of cruising much more pleasant.

jimh posted 09-19-2011 10:16 PM ET (US)     Profile for jimh  Send Email to jimh     
Thanks for the follow-up. It's great to get some first-hand impressions.

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