DIY Sailing Instrument

dLj · Feb 1, 2026

colemj said:
I'd disagree that commercial electronics become obsolete at a rate that is unacceptable. Obsolete means they can't be used anymore, not that the manufacturer no longer makes them. How many 20yr old Raymarine ST60 systems are still being used just fine? Our Vesper AIS, which stopped being produced many years ago, still does what it was designed to do.

Well we are definitely going to have to agree to disagree on this point. A recent example is my autopilot. It's a Raymarine originally pretty high end unit. It's composed of the control panel on my chart table, the computer, the drive engine, the flux gate compass and a remote that can be used to run it from anywhere on the boat. Some other bits like rudder angle measurements.

So the remote started eating AA batteries at the rate of two about every 4 hours. I called Raymarine and they said that they could fix it, just send it in. I do. Then they tell me they can't fix it but they can sell me a new model - called the same thing mind you (I believe it's the ST100) for a discounted price. Sounds good, I buy it they send it to me and wonderful - it won't work with my system. So now I no longer have a remote. I am kicking myself a bit thinking I should have told them to send back mine along with the new one. At least I'd still have the remote.

I talked to them about upgrading my whole autopilot system. There are no new models made that have the functionality of my current model. And they are really pricey! Very disappointing. My unit is obsolete. I essentially can't get replacement parts. Is it still working? Partially. But that doesn't mean it's not obsolete.

My VHF - man that thing is very obsolete! Does it still work? Again partially but I can't get replacement parts to fix the aspects that have stopped working. I can still use it at this point but that unit is just about done.

So a new autopilot is pretty pricey and the installation would require some major work on my chart table as new units don't have anywhere near the footprint of my current unit. Same problem replacing my VHF. Not only is it replace the whole unit, it's remake all the mounting systems. In my particular case, that's a big job. I'm actually letting things obsolese because I might as well change everything I'll need to change in one fell swoop just because of the major rework I'll need to do just for installation of each individual unit.

Now let's compare that to say my steering system. So first of all it's a worm drive system so the likelihood of anything breaking on it is very low. But if something did break on it, I could fix any part that broke and I'd have the same system back up and running. But it will likely keep running perfectly for the next 100 years. It will never become obsolete. Certainly it may become old technology but it won't become obsolete.

There is not a single piece of electronics that doesn't become obsolete. Electronics and seawater don't play well together. And don't tell me "that's just how it is"... I have been involved with making electronics withstand extreme conditions. They can most certainly be made to last many decades.

dj

colemj · Feb 2, 2026

dLj said:
Well we are definitely going to have to agree to disagree on this point. A recent example is my autopilot. It's a Raymarine originally pretty high end unit. It's composed of the control panel on my chart table, the computer, the drive engine, the flux gate compass and a remote that can be used to run it from anywhere on the boat. Some other bits like rudder angle measurements.

So the remote started eating AA batteries at the rate of two about every 4 hours. I called Raymarine and they said that they could fix it, just send it in. I do. Then they tell me they can't fix it but they can sell me a new model - called the same thing mind you (I believe it's the ST100) for a discounted price. Sounds good, I buy it they send it to me and wonderful - it won't work with my system. So now I no longer have a remote. I am kicking myself a bit thinking I should have told them to send back mine along with the new one. At least I'd still have the remote.

I talked to them about upgrading my whole autopilot system. There are no new models made that have the functionality of my current model. And they are really pricey! Very disappointing. My unit is obsolete. I essentially can't get replacement parts. Is it still working? Partially. But that doesn't mean it's not obsolete.

My VHF - man that thing is very obsolete! Does it still work? Again partially but I can't get replacement parts to fix the aspects that have stopped working. I can still use it at this point but that unit is just about done.

So a new autopilot is pretty pricey and the installation would require some major work on my chart table as new units don't have anywhere near the footprint of my current unit. Same problem replacing my VHF. Not only is it replace the whole unit, it's remake all the mounting systems. In my particular case, that's a big job. I'm actually letting things obsolese because I might as well change everything I'll need to change in one fell swoop just because of the major rework I'll need to do just for installation of each individual unit.

Now let's compare that to say my steering system. So first of all it's a worm drive system so the likelihood of anything breaking on it is very low. But if something did break on it, I could fix any part that broke and I'd have the same system back up and running. But it will likely keep running perfectly for the next 100 years. It will never become obsolete. Certainly it may become old technology but it won't become obsolete.

There is not a single piece of electronics that doesn't become obsolete. Electronics and seawater don't play well together. And don't tell me "that's just how it is"... I have been involved with making electronics withstand extreme conditions. They can most certainly be made to last many decades.

dj

You didn't say which AP you have, but Raymarine introduced their current AP 13yrs ago, so it is at least that old. Your comment that the new controller won't fit the space of the old controller leads me to think you have the 7000 system, which is 34yrs old.

We have had all 4 generations of Raymarine AP - the Autohelm-series, XT-series, the S-series, and now the current Evo series. The current model does everything the older models did, and some things they couldn't do. I'm curious of which functionalities yours have that the current model does not?

I don't consider electronics to be comparable to steering systems. However, I must say we have had fewer issues with our electronics over the years than with our cable and hydraulic steering systems. Choosing to compare to a single worm drive system is a bit of cherry-picking to make the point.

Maybe you don't have any newer electronics, but they have improved in ruggedness tremendously. All of our nav instruments have optically bonded trans-reflective screens, single board integrated circuits, and completely sealed housings with IPX7 rating. Even the back connector is waterproof.

The improvement in functionality is almost immeasurable. We have a single 4" instrument that alone does everything the 4 previous individual instruments did, and so much more they could never do. That alone was worth the cost of upgrade, but it did not make the old instruments obsolete in usage (I sold them for 1/2 of the cost of the new ones).

I agree with you that there is not a single piece of electronics that doesn't become obsolete, but will agree to disagree on what that obsolete dignity level should be. 30yrs seems like asking a lot to me.

Mark

colemj · Feb 2, 2026

dLj said:
They can most certainly be made to last many decades.

Forgot to address this part. I replaced 13yr old instruments (brought to market in 1988, but installed on our boat in 1998) on our previous boat in 2010. The reason was a lightning strike - otherwise they were still working as new. The replacements were with the newer type I described above with bonded screens, single integrated circuit board, sealed housings, etc. Those instruments are still working like new after 16yrs, and I would expect them to last at least 2 decades.

"Many decades" is undefined, but most people don't care after 20yrs because they will either have sold the boat, want new electronics for the new functionalities, or experience something like a lightning strike that takes them out for no blame on the instruments.

Mark

dLj · Feb 2, 2026

Let me touch on some of your points and question as to functionality. My current control head has a dial that allows rapid course correction, the two sets of buttons, the +1 and +10 degrees to port or starboard. In autopilot mode, when turning the dial each beep is a degree in the direction you are turning it. There is a button on the unit that turns off the autopilot and that dial will simply drive the boat as if it were wheel steering. Having both of these functionalities on the control unit no longer exists. At least by Ray Marine - I haven't checked other options yet as the unit still works even though I no longer have the remote unit.

I don't want any more bells and whistles on this system. It does not matter to me at all. This unit does everything I want and need. As I run a wind vane, I have no need for an electronic autopilot to run in wind direction mode. I fully understand why one might wish to have that. However, if I could still get parts for this unit, I could do that also, the computer supports that function.

I'd be interested in hearing what you feel are the fantastic advances that I could pine for? As is, this unit can set and hold a course quite well. I can use it as a steering unit if desired. I've run it in all sorts of sea states and it does very well. I could possibly interface it with a chart plotter to run routes but I personally don't like doing that and won't on my boat. I have done it on others boats. If I were doing the ICW a lot, now there I would definitely want that. But I doubt I'll ever do the ICW again as this boat is tough to run the ICW - perhaps if I ever go to a trawler.

Somewhere in the conversation it was mentioned these electronic gadgets make long distance sailing safer as you can arrive at your destination faster. While I agree faster passages are safer passages, I feel faster passages are more the skills of the captain. The single biggest boost to that is Starlink and having high speed internet anywhere in the world. Now that's a serious game changer. But in fact all of these tools create greater risk. The current social consciousness of how these tools make things safer gives the erroneous impression that one can just go buy electronics and you're all set. The biggest factor for a safe passage is a skilled captain. Now, I do have to say that Starlink is a serious game changer and even the best of captains would be improved through the use of that technology.

As to obsolescence - I wasn't trying to use my steering system as a disingenuous comparison - although as you point it out, I can see why you would say that. What I was actually thinking about was that it's a complicated and high dollar bit of kit with many subcomponents. However, in all its complications I would never have to pretty much completely redesign that whole system as I would with an electronic autopilot. I could replace just whatever component broke.

That comparison, however poorly done, was aimed at how we don't design and build electronics to be fixable. It's discard and buy new and who cares how much impact that has on the end user. It's this throwaway mentality, coupled with us as consumers feeding into it with our desires to buy new with new bells and whistles. And all of that couched in what I consider a lie - the "it's safer" lie.

Then it crosses into the whole wastefulness of electronics going into landfills etc, but I'd better stop there....

This is way off topic here in this thread. The OP obviously is having a blast doing all the work. Fantastic! Any reason that gets someone out on the water and enjoying - I fully support!

dj

colemj · Feb 3, 2026

dLj said:
Let me touch on some of your points and question as to functionality. My current control head has a dial that allows rapid course correction, the two sets of buttons, the +1 and +10 degrees to port or starboard. In autopilot mode, when turning the dial each beep is a degree in the direction you are turning it. There is a button on the unit that turns off the autopilot and that dial will simply drive the boat as if it were wheel steering. Having both of these functionalities on the control unit no longer exists. At least by Ray Marine - I haven't checked other options yet as the unit still works even though I no longer have the remote unit.

You were led wrong by Raymarine, or misunderstood them. Their P70RS controller does all of that. Our Simrad controller does also, so that function exists in other brands (and has existed for many years, as it is a primary power-boat function). p70Rs | Power boat Autopilot Control Head | Raymarine

I don't know why this type of control head is marketed toward power boats, because like you I find these knob and manual steering functions extremely useful on a sailboat. So much so that we usually steer the boat around anchorages and the like with the knob rather than the wheel.

dLj said:
I'd be interested in hearing what you feel are the fantastic advances that I could pine for?

The main advantage is performance. The rate compass of the current models is so much further advanced from the old compass that they aren't even comparable. The new AP's anticipate boat and sea conditions based on 9-axes of movement, which allows the pilot to make adjustments to the steering in advance of the boat reacting to the conditions. They don't react - they anticipate like a human. I know you think your current pilot steers your boat well, but you would just need to take my word that after using the new systems, you will look back and realize the old one didn't steer that well.

Otherwise, you don't seem to care about functionality beyond steering to a compass course, so there won't be any additional advantages of going new.

dLj said:
Somewhere in the conversation it was mentioned these electronic gadgets make long distance sailing safer as you can arrive at your destination faster.

I think you misunderstood this discussion. It wasn't about electronics per se, but about how having accurate polars for the boat in different conditions and different sail choices allows more accurate weather routing. This does have some safety component, and can allow a faster passage.

The electronics bit came up in the discussion of how to generate these accurate polars, which isn't a small feat. Just grabbing the polar from the manufacturer isn't very accurate because those are calculated polars based on the boat design for a boat that was probably never built as designed, and certainly no longer meeting the original criteria.

dLj said:
That comparison, however poorly done, was aimed at how we don't design and build electronics to be fixable. It's discard and buy new and who cares how much impact that has on the end user. It's this throwaway mentality, coupled with us as consumers feeding into it with our desires to buy new with new bells and whistles. And all of that couched in what I consider a lie - the "it's safer" lie.

The inability to fix electronics is inversely proportional to the robustness and longevity of the electronics. It is a very good thing these small electronics are now single integrated circuits optically bonded directly to the display inside a completely sealed housing. All of the problems like moisture in the screens, polarizing film burning, electrolytic caps popping, ribbon connectors between sub-boards breaking, etc are gone. The entire instrument is basically a chip bonded to a screen.

How do you fix something like that? All components are microscopic surface mounts, and all functionality is contained in a single microprocessor. The displays are bonded, so not replaceable. It is like complaining that a modern computer containing a microprocessor with integrated memory, floating point processing, ALU, GPU, I/O, etc is no longer fixable like the old ones that had separate chips for all the functions.

Or like complaining you can no longer replace vacuum tubes in your TV or radio.

Mark

High Current · Feb 3, 2026

Do you know where the GPX <course> and <speed> elements are defined? It seems like they're not part of the GPX standard, but they're de facto standard parameters.

More to the point: are there comparable ones for wind?

colemj · Feb 3, 2026

I forgot to mention that we have two complete and separate autopilot systems. Both are current models from each manufacturer. The primary is a B&G NAC3, and the backup is a Raymarine EV400.

I mention this because dj has considered updating his AP, and I have had a lot of time directly comparing the B&G with the Raymarine, as they run side by side on our boat.

The B&G is significantly better than the RM in heavier conditions. It has better steering algorithms and continually monitors and automatically adjusts its steering parameters for conditions. The B&G rudder feedback sensor is also more responsive and precise than the RM (who still uses their very, very old sensor from the 90's). The B&G also has the smarts when operating in wind mode to automatically switch between AWA and TWA when the wind is aft of the beam. This allows one to sail a better course upwind, while preventing jibes downwind. The B&G compass also provides heave and yaw data, and the AP processor algorithms use these data. This isn't a minor point - the system can detect when the boat is rising to a swell and about to surf and make steering adjustments before this actually happens. The system steers better than most helmspeople (is that a word? Helmsmen seems sexist).

The Raymarine system is still very good. It is much, much better than the RM systems it replaced. Most of this is likely due to the better 9-axis MEMS rate compass compared to the older physically gimbaled fluxgate. I think the steering algorithms are the same as the older models, as that doesn't seem significantly improved, and one still needs to manually set the steering response for changing conditions. One thing it does do better than the B&G is that its compass will automatically calibrate and correct itself as you move around. It will continually update this. The B&G requires one to go out and do a bunch of circles at a prescribed turn rate.

I can anticipate conditions that would overwhelm the Raymarine AP, or at least require constant vigilance on the response levels and being ready to take the wheel if it loses control down the face of a wave.

I don't anticipate conditions that would overwhelm the B&G and not be conditions where we would be in a more survival mode like under drogue or hove to.

Mark

colemj · Feb 3, 2026

brett_howard said:
Well shit... I thought I'd finished putting all the wind data into the GPX files... But as it turns out nope... Here is one from a few years ago. Really cool that I do have years of sailing data and all the trips I've taken. But alas I don't have all the wind data so I can't turn it into polars. Looks like it was going to be a pretty simple thing to do and get out a polar. The only tricky part would be filtering for the right values. But that is the fun part!

I don't know anything about what you are doing other than the overview words you have described it with. With that said, can you make a subprogram or independent hardware bit that just logs wind speed, angle, and boat speed? And output this in a format that feeds directly into a spreadsheet file? Kind of a polar generator function?

It's probably easy enough to just filter out those data from all the others in your existing data file, but having it separately might be easier and allow you to watch the polars being built while you are under sail. This is how the OCPN polar plugin presents itself, and I find it useful to see the data set being built to see if something is odd (like the wind or speed instrument isn't calibrated correctly tack to tack, or current is really messing things up).

And that just reminded me of another point. SOG isn't useful for polars unless you can absolutely rule out current or sea state interference. You need SOG for polars.

Mark

colemj · Feb 3, 2026

colemj said:
SOG isn't useful for polars unless you can absolutely rule out current or sea state interference. You need SOG for polars.

Oops, I meant you need STW for polars.

colemj · Feb 4, 2026

I thought the ring of led's would show AWA, but they seem all lit up. Or are the two yellow ones in the green sector the angle? If so, this seems confusing (and a bit ugly) vs just having lit led's at the AWA itself.

Particularly if one is color blind!

Mark