Si-tex SP36 autopilot

[Matt Johnson]

Anyone familiar with the Sitex autopilot system? Defender currently has them for $1300 (reg $3200) with the pumpset. The typical players...Raymarine, Simrad and B&G are great set-ups, but at $2000 without any pump (I would sell the pump that comes with the sitex) it makes this seem like a great deal.

It is more of a powerboat computer, but I'm not sure what the difference would be vs a sailboat version besides steering to wind. If it works as good as our current Raymarine XP10, I would be happy with the Sitex and save good money. It does at least come with Sitex's version of the Airmar gyro and I'm sure that helps it steer a good corse.

We bought a new 37' sailboat and need to get a new autopilot system for it (it has a old Raymarine wheel), but don't want to put in something crap just to save a few bucks.

Matt

[colemj]

I looked at that when you mentioned it on another thread. The computer itself seemed fine - it even lists steer to wind as one of its functions, which wouldn't be very useful to a powerboat. In fact, I can see no difference between the computer and control head specs between the models aimed at powerboats and sailboats.

So the stickler is the drive unit. Defender lists a sailboat drive package for $1,200. However, the drive unit is a teleflex cable type connected to a rotary drive. The specs are very low on it, and the mounting engineering seems pretty dicey. Personally, I would not want our boat relying on it.

It is also listed for a maximum displacement of 15,000lbs - most 37' mono's exceed this (most 37' catamarans do also!).

IMO, autopilots are just too important to dick around with. Scrimp elsewhere, but put good money and good engineering in the autopilot. Don't try to "make something work" here - save that for other things!

Mark

[Matt Johnson]

Mark, I should have posted the link in the OP, but the one I posted before was the 110 model and a smaller unit. They also have the SP36 which seems to be equivalent to a Simrad AC12 or Raymarine ev200 (x10)... the pump this package comes with is useless to me, but could be sold and replaced with a type one linear drive.

Si-Tex SP36-5 Autopilot System

[colemj]

Ah, that one is different than the one I looked at. You would need to sell the pump for a good price and buy a linear drive (if that is what you need). The linear drive will cost ~$1,800 - I don't know what the hydraulic drive could sell for, buy I'm guessing no more than $500. That leaves you holding the bag for at least another grand.

So all up, you have ~$2,300 in the system, which is a bit less than an equivalent Raymarine or Simrad, but not much less. Still, might save a few bucks.

Mark

[Matt Johnson]

Since you can purchase the Raymarine kit with linear drive for $2650 right now, maybe it's not enough to make an unknown worth it. The Sitex is built for them by Comnav, and they have a pretty good rep....who knows.

Matt

[Matt Johnson]

Quick update.... Just received an email from Si-tex regarding their SP36 system. Seems they have updated their autopilot systems software to include steering to wind and wind point functions. It's now set-up for a sailboat.

I've placed an order and will post when I have the new boat in the water....it won't be for awhile since we have to sail back to the US (it's in Florida) and work on it first.

Matt

[deblen]

ComNav Marine Ltd. - Products Index

I believe you will find the Si-Tex pilots are built by Comnav Marine.
Comnav make excellent pilots.
I was in marine electronics for 30yrs-commercial fishing boats mainly.
I sold & serviced most of the major brands,& Comnav is one of the best.
Believe it or not,most Ap will steer the Queen Mary,as long as it has a good heading sensor & the correct drive unit for the rudder. The drive unit is where most performance problems occur.Also,you can use many different brands of drive units.ie: mix & match. You are not limited to using the same brand of drive as the the control unit.
Many of the entry level/inexpensive AP's skimp on the drive unit to keep the pkg price down.The electronics,for the most part will work just fine.
Another problem is that first time AP owners expect the pilot to sreer a perfect +/-1deg. course in all sea conditions.Won't happen!
Some boats steer better than others. As a test,take boat out in 3-4' stuff.Manually steer the boat,under power,in four 90deg. different directions.Get on a course & hold the tiller/wheel steady-do not turn it. Note how many degrees the boat wanders back & forth in each direction,by watching your steering compass.This wander is "normal".
Don't ask a pilot to steer any better,or it will beat the drive/rudder system to death trying. Also,your eyes let you react to an oncoming sea before it hits/affects your boat.An AP has to wait for the boat to be knocked off the set course before it can react.
A good helmsman can steer a tighter course than any AP,over the short term.An AP may let the boat yaw a bit more than a human in the short term,but will steer a better average course in the long term,cuz it never takes its eye off its compass. Jus my experience & opinions. Cheers /Len