My New Plotter - a Cautionary Tale

I recently replaced my Standard Horizon plotter, the antenna filled up with water and failed. SH uses powered remote GPS antennae so if you have one, take it apart and make sure its not leaking, they cost about 325 dollars.

This, however, is not the problem now. I purchased a Si-tex 760 plotter to replace the dead SH as I had had very good service (25 years) from a Si-tex sounder. I installed it, the satellite array is good with an average of 9 satellites and the HDOP measurement is .82.

While coming out of Malaspina Inlet the other day and while dodging a 50-footer high and dry on the rocks, (no photos, I was busy! Coast guard etc.) I noticed that the plotter was a little "off." My ipad backup was bang on visually but the Si-tex was 2-300 meters behind. When I changed course, the ipad responded instantly but the plotter did not and it stopped at an intermediate course, not the new one. If I had followed the plotter without looking out (not an option) I would have followed a bogus course. The ipad has never let me down even with an internal gps and no way of monitoring the signals.

Si-tex is now digesting this and has suggested a software upgrade, which begs the question, if this had happened 6 months ago and this issue existed then, how could it be sold with such poor software? Why didn't they upgrade this before selling it to me? Now I am in their hands and I will see how they and their dealer, Mackay Electronics, deals with this issue. I have lost faith in this plotter and will need it replaced, I might even spend more if it they make another device with better processor and software...

The lesson here is not that a particular manufacturer makes shoddy devices but to NOT just trust that fancy new box with the lives of your boat and crew. Test it out carefully and have a good backup.

For now, I will put a second I pad on the dash and carry on.

"The lesson here is not that a particular manufacturer makes shoddy devices but to NOT just trust that fancy new box with the lives of your boat and crew. Test it out carefully and have a good backup. "


Good point. Redundancy is the key to many things on a boat, electronics being one of them


Please keep us posted about what happens with Si-Tex and your dealer.

Two lessons:

1. Redundancy

2. When you purchase from a retailer, you're not necessarily getting current. They could have easily shipped this to a distributor or dealer before the upgrade to the software and before discovering the problem. Packaging or something in it might have given a clue to the date with code or something. In purchasing any electronics at retail, the first thing needing to be done is often a software upgrade. Should the dealer have done that? Probably. You buy the latest greatest computer today, just shipped to the retailer, and you can be certain there are upgrades for much of the software on it. Cable company brings in a new DVR, in the new box, hooks it up and first thing it needs is a software upgrade. If a phone has been sitting in the store a month, it might well need an upgrade. A dealer or installer should have been aware, but it's difficult to keep up with them all.

BandB that's all true but you will have a hard time convincing me that a software upgrade on a cable box compares to a software upgrade on a plotter that should have been accurate out of the box despite any software issues.

I will certainly keep you updated, these are both large companies.

I just purchased a SI Tex Auto Pilot. I had a few questions and they were very responsive. Interested to know how you make out. I was considering one of their plotters. I like to reward good service that is so rare in the present world.

Xsbank said:

BandB that's all true but you will have a hard time convincing me that a software upgrade on a cable box compares to a software upgrade on a plotter that should have been accurate out of the box despite any software issues.

I will certainly keep you updated, these are both large companies.

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The procedure is the same even though the criticality vastly different. Obviously, the plotter software had an issue. Should have been recalled until updated in all likelihood and certainly dealer should have been informed but they're often poorly managed. I'd look to see how old the plotter is, when it was manufactured. I'm always skeptical of electronics and time sensitive items sitting on retailer's shelves. It happens on mechanical equipment too. I've known boat builders installing engines in new boats that were manufactured two to four years earlier.

The prudent mariner always has two means to determine his position.

The word I received a few moments ago is that the included Navionics chip has had some flaws in its operation and so they are sending me a C-Map chip to try. I send them the old one back. If this solves the problem, all is well. I have had Cs before (Jeppeson) and like all their stuff and a history of flying with Jepp plates, I trust them.

So far these guys get an "A" for their customer service, both the dealer (Mackay) and Si-tex.

For the record, I have a Koden radar which is as old as the hills, takes 3 minutes to boot up but works like a charm. Also a Si-tex product.

In addition to redundancy, I think the other caution is to place all new equipment on probation until it has been demonstrated to be accurate and reliable.

twistedtree said:

In addition to redundancy, I think the other caution is to place all new equipment on probation until it has been demonstrated to be accurate and reliable.

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+1, electronics as well as other critical equipment.

" The prudent mariner always has two means to determine his position."


In most cases the eyeball MK 1 -mod 0 does the best .

Xsbank said:

The word I received a few moments ago is that the included Navionics chip has had some flaws in its operation and so they are sending me a C-Map chip to try. I send them the old one back. If this solves the problem, all is well. I have had Cs before (Jeppeson) and like all their stuff and a history of flying with Jepp plates, I trust them.

So far these guys get an "A" for their customer service, both the dealer (Mackay) and Si-tex.

For the record, I have a Koden radar which is as old as the hills, takes 3 minutes to boot up but works like a charm. Also a Si-tex product.

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Glad they're providing great service. Still would have been nice had they warned you rather than waiting until you have an issue with it. What if you'd been a novice and blindly trusted?

Xsbank said:

For the record, I have a Koden radar which is as old as the hills, takes 3 minutes to boot up but works like a charm. Also a Si-tex product.

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The other way around I'd think.
Koden is a manufacterer of commercial equipment and sitex is the offshoot.

I bought a Sitex CVS-126 sounder because it was a fair bit cheaper than the Koden.
I peeled off the Sitex sticker and it says koden underneath.

Could it be that the plotter only picks up GPS satellites?

I notice with my seiwa plotter that it'll drop out while my android tablet and phone still have plenty of satellites, but I rooted both of them so the now pick up the Russian glonass satellites as well.

Pretty sure older apple stuff didn't use the Russian system but maybe they have got with the program on the newer models?

Never rely on one source of navigation position.
Never rely on any equipment that hasn't been proven that may effect your safety.

Never and always are words I hate to use but in this case I'll take the plunge. ?

Plunge away! I'm curious if there is a problem with this particular Navionics chip, Navionics Gold, there might be more of them out there putting us at risk? I wonder if there is a reliable source with this information?

I think more likely that this is due to a conflict with another device on the boat. I found that my Inreach caused my iPad with iNavx to demonstrate considerable bias in horizontal position when the two were connected by Bluetooth. Try switching off devices to see if the results change.