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Side-stepping the technical silos

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Graham W:
This is a long one, probably of interest to gadgeteers only.

I regularly fume about the pricing policies of the big boating electronics companies (Garmin, Raymarine et al) that sell us GPS/fishfinders and the electronic charts that these use.  The electronic boxes are extraordinarily expensive - think how much a large HD screen smart TV costs by comparison.  And once you are tied into their ecosystem (or technical silo), if you want to keep your charts up to date you also have to pay them an enormous annual subscription.

At the same time, navigation apps that we can use on our tablets and mobile phones have been improving by leaps and bounds.  Significantly, you are not tied to one silo, there is a lot of competition and consequently subscriptions are substantially cheaper.  There are free trials of several apps so that you can see if one or other suits you better.

The main problem with using tablets for navigation up until recently is that robust and waterproof versions were very expensive, or non-existent for Apple iPads without a protective case; the screens weren’t bright enough to be sunlight-readable; and the touch screens weren’t usable in the wet.  This is also now changing as an enterprising Belgian sailor decided that existing tablets weren’t sufficiently suitable for use on the water and set about specifying one that was.  The result is the Sailproof Android tablet in 8” and 10” versions.  Drop proof, waterproof, having a bright sunlight-readable screen, a touch screen usable in the wet and with gloves, a highly accurate GNSS receiver (it picks up the relatively new EU Galileo satellites as well as the older and less accurate US and Russian ones), SD card-based expandable memory and a large battery that can easily be swapped out.  See https://sailproof.shop.

While I was fuming away about Garmin and others, my ancient iPad was becoming increasingly unreliable and my Garmin fishfinder was also long in the tooth and would need replacing soon.  It was no longer compatible with Garmin’s expensive new charts.  Not being technically proficient like Andy B with his astonishing Kindle-based system, I needed to rely on off-the-shelf solutions. 

To kill two birds with one stone, I bought a Sailproof 10” tablet with a spare battery - total cost including courier charges and UK VAT was £810.  I already had quite a collection of mostly secondhand Tacktick wireless instruments and transducers - yet another technical silo but still going strong and a sunk cost.  The only questions were whether there was a method of transmitting Tacktick data (wind, depth, water speed) to the tablet and then whether there were navigation apps that could process this data in a user-friendly way.  It turns out that the answer was yes to both.

I bought one of the cheaper Digital Yacht multiplexers that collects the data from the Tacktick system using the NMEA 0183 protocol and then broadcasts it over wifi to the Sailproof tablet.  Android and Apple tablet apps like Navionics, Memory-Map and Android-only OpenCPN then take this data and publish as much or as little as you want to see, as numbers or as on-screen instruments.  This is alongside excellent user-friendly charts and their own computed navigation data.  You can use their suggested auto-routing, waypoints,  tracks, VMC, wind indicators and all the other bits of information that I find useful and interesting.  Screen grabs below of some typical screens, taken whilst stationary in my kitchen.

The only reductions in functionality that I have found so far compared to my old Garmin/Tacktick system is that the NMEA data only flows from Tacktick to Sailproof but not vice versa.  So for example my Tacktick display doesn’t show the VMC calculated and displayed by an app on my Sailproof.  And I no longer have a fishfinder screen showing the serial changes in the depth contours under the boat - there is just a depth number or dial with configurable alarms.  There may be apps out there that can perform this function but I haven’t found one yet.  On the other hand, because I had to buy a new depth transducer to replace the Garmin one, I chose a triducer with a water speed paddle wheel, so I can now compare boat speed through the water with SOG.  How long the paddle works reliably remains to be seen. 

The Sailproof’s 1m positional accuracy is better than the old Garmin’s and iPad’s, both of which relied on the US and Russian satellite systems.  I was trying out a ‘fisherman’s shortcut’ between rocks off the south of Barra at low water, following an Antares chartlet on my iPad (see screenshot below).  I could see that if I slavishly followed the app’s route, I was going to end up on the port side rocks.  The Garmin wasn’t much better.  A narrow but visible gap between the kelp strands on each side showed me the way.

I have been pleasantly surprised by how little I have had to pay to change from Apple apps to Android versions, as most of the apps that I use are free or on an annual subscription basis and can be used in either system at no additional cost.  Being armoured, the Sailproof is a real brick compared to the old iPad and is about the same price as an equivalent new iPad with a chunky case - except that the latter’s screen isn’t quite bright enough.  On the other hand, even my old iPad’s screen is higher definition, perhaps the price to pay for pushing the Sailproof’s screen brightness without unnecessarily hammering the battery.  The Sailproof is quite fast and I can use it for all the non-sailing activities for which I used to rely on the iPad, like picking up emails, Zoom calls, listening to Radio 4 on BBC Sounds and reading the newspapers on PressReader.  Try doing that on a Garmin! 

There are cheaper Android alternatives to the Chinese-manufactured Sailproof.  For example the robust Oukitel RT2 (also made in China) shares many of the Sailproof’s specifications for around half the price https://www.amazon.co.uk/dp/B0BFX2X7TS/ref=sspa_dk_detail_0.  Its battery is twice as large but it has a very substantially dimmer screen - worse than the one on my old iPad.  I’ve found one comprehensive technical review of this tablet translated from the original German https://www.notebookcheck.net/Oukitel-RT2-review-Extremely-robust-outdoor-tablet-for-the-construction-site-with-monster-battery-and-LTE.665464.0.html.  It’s not very complimentary about some aspects of the tablet and particularly highlights the lack of sunlight readability.  The few short reviews of the Sailproof are enthusiastic but are not technical and are mostly to be found in sailing magazines, written by non-IT experts.  Perhaps a more viable Android alternative to the Sailproof is the Samsung Galaxy Tab Active4 Pro, which has a much smaller battery and brighter screen compared to the Oukitel, but still not as bright as the Sailproof.  There is also the Tripltek 8 Pro, which has the brightest screen of all at 1200 nits but is only available in an 8” version.  Attached below a technical comparison of these various tablets, plus the iPad 10 and an iPhone.

It’s early days for my new system.  Like many, I was expecting someone to come along with integrated tablet-based systems based on Bluetooth but it hasn’t yet happened.  Perhaps Bluetooth isn’t yet reliable enough compared to NMEA over wifi, which was suggested as the alternative by AndyB.  In the absence of a Bluetooth solution, I’m happy to pay extra for an NMEA multiplexer that reliably does the communications job, while allowing me to side-step the technical silos of the price-gougers.  Rob J and others emphasise how important it is to have redundancy in systems in case the main system dies and I have an Apple iPhone 8 in a waterproof case that can act as backup to the Sailproof.

One of the developers of a clever tablet navigation app started discussions with a prominent price-gouger about possible cooperation.  Somehow the subject arose about what a threat tablet apps pose to the electronic box market leaders.  It was suggested that the latter can no longer fight back by acquiring upstarts and then stifling or neglecting them, as Raymarine did with Tacktick.  The discussions were abruptly terminated by the price-gouger, which probably tells you all you need to know about where the future lies.  Even Garmin have hedged their bets by acquiring Navionics.  In a break with tradition, they have continued to develop and improve the Navionics mobile app, even as it takes market share from one of their own core electronics businesses.

Timothy W:
Thanks for this post. It answers a number of questions for me. When you’re finished, please post a picture of how you mounted the tablet and other displays.

Llafurio:
For a few years I am using the Navionics Boating App on a waterproof mobile phone with large battery, currently a Doogee S96 GT. https://doogeemall.com/en-de/products/doogee-s96gt-8gb-256gb-ai-quad-night-vision-camera-6350mah-large-battery-more-rugged-phone.

When needed, it is held firmly in position on the centreboard case by a self adhesive strip of Velcro.

Works better for me than my previous in-built Lowrance GPS units with charts on SD cards.

AndyB:
First of all let me just say I have no real usage of Tacktick instruments, but did research them a while ago. They have a proprietary wireless system which is a pier system and as such does not need a central hub. They pass messages between themselves. To connect to the outside world they use a special gateway called a T122. If you have one of these then you could try connecting an output of your multiplexer ( you do not seem to mention what it is) to one of its inputs. The documentation that I had said that the T122 could receive DPT, HDG, MWV, RMB,RMC,VHW which I then suspect will be transmitted to each of the Tacktick devices. VHW is speed through water.

So if one of your transducers can produce VHW and your multiplexer can transmit it you should be able to achieve what you want.

Look for your multiplexer outputting (WLN30 has this feature) which outputs NMEA to a physical wire which you connect to a T122 using normal 2 core cable.

Not sure how you get a depth timeline as not sure what sailproof has but if there is a Node Red application then I suspect you could get a depth timeline.
Hope this helps
Andy B

AndyB:
Forgot to say. If you have android on the sailproof then NMEA instruments wirelessly looks a good app.
https://www.encodedsolutions.com/nmeainstruments.php
Andy b

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