Autopilots on small vessels.

[Danf]

I am familiar using autopilots on larger boats, 40ft at 20 knots. I would like to install an autopilot into a smaller boat, a 5.2 Kevlacat and am wondering if these units are as stable in response as on a larger vessel.
I see that some of the entry level autopilot units use a less sensitive heading compass, and research shows that a better response/performance is achieved by using an upmarket sensor.
One such unit is the Simrad unit which will interface to a Simrad plotter, and getting a Precision 9 heading sensor should give reasonable results at fast and troll speeds, within acceptable weather conditions.
The balanced hydraulic cylinder is around 180cc, so the small pump will be fine. The unit on the larger vessel is a Raymarine with rubber feedback and this vessel is 12 tonnes, so it tracks pretty well in all conditions. The Simrad unit uses a "Virtual Rudder", which probably means that the software infers a rudder feedback by using the array of information from the heading sensor.
I have not driven any small vessels fitted with autopilots, so I am interested if anyone has experienced this.

[ranmar850]

I have the Raymarine EV 150 (?) on my Reefrunner. It is just brilliant. Far better, in fact than the older style autopilots that used to be fitted to larger vesssels.And I have plenty of experience in this, I skippered commercial fishing boats 38 to 50 ft for 26 years, all had autopilots, usually Furuno, Simrad or Robertson. No need for a rudder feedback unit any more, the heading sensor takes care of all of that. Just mount it somewhere near the centreline, away from strong electromagnetic fields. i use mine all the time, has never given me a bad moment. Moose might like to add to this, but the difference between the cheaper ones ( like the Lowrance) vs the Raymarine is not the response at higher speeds, but the low speed useability. Mine just tracks dead straight until you are actually at so low a speed heading into a fresh wind that you couldn't keep it straight on manual steering. Cannoit recommend highly enough. if you think they are not excellent value, you haven't spent any time using one, to be blunt.

[Greg P]

I have the Simarad AP on my Haines Signature 543SF. I had some issues with magnetic interfernce for the Precision 9 compass initially due to the accessible location to mount the compass without magnetic interference but have since sold the P9 and went with a HS60 (GPS Compass). I'm running the NAC2 through a NSS12 EVO 3 and control the AP through the Evo 3. Also have a remote to control the boat while playing a fish solo. System is mint and works well but I would say in a small boat you need to look at some sort of man overboard system (just in case) especially if you go out alone and use the AP. I have the Fell Marine MOB installed and just wear a FOB like a watch while on board.

I think AP are a good have if you can afford it and like trim tabs once you have one you will always see the benefits and have them on you boat.

[Danf]

Looks like magnetic interference seems to be the achilles heel of the autopilots.

[baitable]

Looks like magnetic interference seems to be the achilles heel of the autopilots.

not if you have a heading sensor on your roof. I have a furuno system with the scx20 and it performs flawlessly... its not exactly a budget system though...

[scottar]

Installed more pilots in small boats than I've had hot dinners (so to speak) over the years. Smallest of which was my 4.5 metre tinny that got used extensively for trolling for flathead, barra, macks and anything else that would eat a chunk of plastic. It did get used at speed on occasion but being a light boat keeping an eye on the ocean (and more so hanging onto the wheel at speed) was a better option, Some years later I installed a full hydraulic set up which allowed far better control (it was mechanical initially) and also allowed hanging on without issue. Current pilot on a 6 metre rig is not only great for trolling but also allows for either keeping a better watch on transits - you are looking where you are going without having to worry about whether you are off course or at times allows you to keep a better eye on your sounder as you know where the boat is going. It also reduces fatigue on long transits.

Simrad pilots.............Put it straight out there - not a fan of Navico - Is what it is. Don't look at a minimum sized system if you do go down this path and purchase from a dealer that is both technical and local so you are not trying to sort it over the phone as at times the help is .........let's just say less than exceptional from Navico themselves. Minimum I would be looking at is NAC2 based system and definitely NOT the pump they sell for outboard only steering.

Rudder feedback-less autopilots - some have gotten a lot better but set up properly, a pilot with a feedback will steer better - they wouldn't bother making them if they didn't. With a feedback a bit of air in a steering system or slop in a linkage (provided it's not the feedback's linkage) is less of an issue as the pilot puts the rudder/outboard where it wants it - doesn't assume it's gone there by using timing based drive. You may not need one but personally I would always recommend a pilot that at least has the option of a rudder sensor if required. Personally I run a TMQ pilot (worked for them at one stage). I can troll at idle in slop without issue - adjustment of rudder parameters is required in the menus between high and low speed but the fact that the pilot as soon as it gets off course can put on a precise large amount of rudder without having to wait for the boat to drift further off course allows tuning to sea conditions. Rudder sensors for outboards can be a bit tricky but there are a couple of options. Some manufacturers sensors aren't real waterproof which is an issue. On cats with centre steering, a Seastar smartstick can be a good option. Rotary units are definitely trickier to install but it can be done. Prior to leaving the industry, I had seen good results from Garmin feedback less pilots and have had reports also that the Raymarine units do now work well.

Heading sensors - as with any compass - can be effected by magnetic variation. Typically a metre of separation is sufficient from magnetic influences - speakers, pumps, other compasses, boxes of fish hooks or tools, large current carrying cables etc. and while down low on the centre line is the "ideal" option, on a lot of boats it is simply not practical. On a typical "half cab" a pretty common option is halfway up the port side under the gunwale (assuming there are no speakers there). Indeed this is where mine is located without issue. As mentioned, a satellite compass can be a good work around for magnetic influence as well.

[ranmar850]

Looks like magnetic interference seems to be the achilles heel of the autopilots.

Not hard to deal with , at all. Just don't mount it right on top of something magnetic, just like with a regular compass. Mine is just over a metre from my dual displays, and about the middle of the two stereo speakers, so, just over a metre from each. The largest EMF would be from the autopilot pump itself, around 1100mm away, no problems at all. If you are concerned about magnetic fields, there are plenty of apps out there you just put on your phone, that actually measure magnetic field strength.

[Out-Station]

Danf, after never having a pilot and then putting one in my 6.8 platey a couple of years back i recon they are game changers in terms of ease of running the boat. I've got a garmin reactor unit (no rudder sensor). I went to some extra trouble to ensure optimum placement, (forward, low and away from electrics etc) of the heading sensor. Getting this right is always going to involve some compromise in a small boat but my advice is be willing to sepnd some effort in doing what you can as it made a difference to performance for me, particularly at slow plane and in sloppy conditions. Also worth spending some time fiddling around on the lake getting the calibration and course graduations etc settings right for your circumstances I find myself using mine all the time, travelling between spots no matter how far, heading hold idling forward whilst on fish, really useful when your fishing solo etc. Great thing imo!!
Scott

[scottar]

Danf, after never having a pilot and then putting one in my 6.8 platey a couple of years back i recon they are game changers in terms of ease of running the boat. I've got a garmin reactor unit (no rudder sensor). I went to some extra trouble to ensure optimum placement, (forward, low and away from electrics etc) of the heading sensor. Getting this right is always going to involve some compromise in a small boat but my advice is be willing to sepnd some effort in doing what you can as it made a difference to performance for me, particularly at slow plane and in sloppy conditions. Also worth spending some time fiddling around on the lake getting the calibration and course graduations etc settings right for your circumstances I find myself using mine all the time, travelling between spots no matter how far, heading hold idling forward whilst on fish, really useful when your fishing solo etc. Great thing imo!!
Scott

Garmin are what I would term a "feedback without feedback" pilot. They don't just rely on timing like others. They actually use a feedback sensor on the pump that counts rotation - thus fluid volume that has been pumped. It works well provided there is no air in the system.

[Danf]

Thanks for the replies.

[TheGurn]

Had a near miss out at caloundra wide while anchored one night.
All on board were sleeping bar me. Saw the red and green coming from a fair way off. Kept coming and coming, and coming.
Last minute flashing torches had no effect. Neither did the anchor light (always on) and finally nav lights.
6mtr (+) boat at a fair speed missed us in a wide open blue ocean by less than 10 mtrs. Kept speed and course when past us.
Unattended autopilot (can you do that? ) or just an ignorant idiot? Or both?
Too quick, dark and terrified to get the rego.

[blacklab]

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[blacklab]

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[Danf]

Had a near miss out at caloundra wide while anchored one night.
All on board were sleeping bar me. Saw the red and green coming from a fair way off. Kept coming and coming, and coming.
Last minute flashing torches had no effect. Neither did the anchor light (always on) and finally nav lights.
6mtr (+) boat at a fair speed missed us in a wide open blue ocean by less than 10 mtrs. Kept speed and course when past us.
Unattended autopilot (can you do that? ) or just an ignorant idiot? Or both?
Too quick, dark and terrified to get the rego.

It probably can happen. Driving home on autopilot in the late evening and not being vigilant, before you know it you've run into somebody.

[scottar]

Had a near miss out at caloundra wide while anchored one night.
All on board were sleeping bar me. Saw the red and green coming from a fair way off. Kept coming and coming, and coming.
Last minute flashing torches had no effect. Neither did the anchor light (always on) and finally nav lights.
6mtr (+) boat at a fair speed missed us in a wide open blue ocean by less than 10 mtrs. Kept speed and course when past us.
Unattended autopilot (can you do that? ) or just an ignorant idiot? Or both?
Too quick, dark and terrified to get the rego.

Nothing more than poor watch keeping practices from a dimwit skipper - deliberate or otherwise. With the advent of GPS plenty of numpties make a habit of high speed flybyes to ping marks.

Yes, the helm can be left unattended and I have witnessed practices that I would never endorse - including filleting fish while running solo on autopilot. There certainly have been plenty of incidents over the years where poor practice combined with autopilot use has resulted in property damage and probably even loss of life. A lot of these involve slow boats - trawlers, long liners and so on where long hours are spent at the helm at mind numbing speeds. In a small boat at speed inadvertent wave action can most definitely result in vessel movement that a pilot has no chance of counteracting smoothly so leaving the helm position can't be regarded as a good idea - period.