How to setup Boat Beacon AIS Sharing to OpenCPN

Get live AIS ship positions around you in the OpenCPN app on Windows, Mac, Android and RPi without the need for an AIS receiver.   Boat Beacon can now share its real time AIS feed from our global AIS aerial network via NMEA with OpenCPN on the same device or on the same Wifi Network. Boat Beacon acts as a “Virtual AIS Receiver” and is the first and currently only app out there that offers this .  The Boat Beacon AIS Share feature is free to try.  If you find it useful you can use it any time when you are out boating for a small monthly or annual subscription via IAP.   You can get the latest version of Boat Beacon from the Apple App Store here and Google PlayStore here.   This is a step by step guide on how to configure Boat Beacon AIS Sharing on iOS (Android guide here) with OpenCPN running on a Windows PC or Mac. Boat Beacon and OpenCPN must be running on the same Wifi network or device. The guide uses Boat Beacon’s demo mode so you can try for free at home away from the coast and without having to purchase an AIS sharing subscription.  

1. Launch Boat Beacon and go into Boat Beacon settings and turn on “Demo Mode”, then turn on AIS Sharing. It will show the IP address (192.168.7.111 in this case) and default TCP port number to use 5353 and will be orange ( not connected). Remember the IP address for use later in OpenCPN. N.B. If you are not in the UK the demo mode will be centred on San Francisco bay in the US.  

  2. Tap Done top left and go back to the chart view. This will position the map on a virtual boat in the Solent ( or San Francisco Bay). All the other boats in view are real and live. Tap the sailboat icon bottom left to start sailing the demo route.

  3. Now switch to the OpenCPN app on your PC ( or Mac) and position the map on the same demo location as Boat Beacon, Solent ( or San Francisco Bay).

On windows click the Spanner icon to open the Options Dialog which has 6 tabs, as seen below. On Mac click Preferences under OpenCPN top left in the toolbar.

Tap Connections, Add ConnectionScreenshot 2021-08-02 at 16.00.09.png

Select Network, select TPC for the protocol, enter the Address (192.168.7.111) and DataPort number (5353) from Boat Beacon. You can enter a User Comment (e.g. Boat Beacon AIS) so you can distinguish this connection from any other connections you add. Leave everything else as default for now.

Screenshot 2021-08-02 at 15.51.32.png

Tap Apply to save and create the new connection and you should see this with the new Boat Beacon connection enabled:-

Screenshot 2021-08-02 at 15.53.40.png

The Settings are persistent, meaning that settings entered in one session will still be there on restart. The live AIS data from Boat Beacon will then display in OpenCPN.

Please note Boat Beacon will use your GPS position ( in non demo mode) to fetch and share the AIS data from (not the displayed map position) so OpenCPN will need to be centred on your GPS location too.

Notes:

  • Boat Beacon must be in Sailing mode to maintain the AIS feed when it is in the background ( e.g. when you are viewing the Navionics Boating app) on your device.
  • Make sure you have Location sharing for Boat Beacon set to “Always” in your device Privacy/Location settings. Please note Boat Beacon will only use your location when it is running ( foreground) or in Sailing mode. It will not “Always” use your location – it’s just an unfortunate terminology from Apple.
  • You must have an internet connection though (e.g. Cellular/Mobile) for Boat Beacon to receive the AIS data.
  • iOS14 has introduced a new privacy permission if apps want to use local network resources which both Boat Beacon  and Navionics need to have set to yes. The OS will prompt you the first time either app tries to use a connection. You can manually set/change the permission in your device’s Settings/Privacy/Local network. See screenshot below for how we have it set.
  • Might sound obvious, but it has caught a couple of people out. You need to subscribe to the monthly or yearly AIS Sharing feature via IAP ( tap the AIS Sharing row in Settings to bring up the IAP screen) to use Boat Beacon with Navionics when not in demo mode.
  • If you have any questions or problems getting it working please email us at help@pocketmariner.com

 

Setup Boat Beacon Android AIS Sharing to Navionics Boating

Get live AIS ship positions around you on the Navionics Boating app without the need for an AIS receiver.
Boat Beacon can now share its real time AIS feed from our global AIS aerial network via NMEA with Navionics on the same device or on the same Wifi Network. Boat Beacon acts as a “Virtual AIS Receiver” and is the first and currently only app out there that offers this .
Navionics have worked closely with us on this with their Boating app  AIS feature and recommend Boat Beacon in its own category in their  Boating app – AIS Devices Compatibility Guide.
The new Boat Beacon AIS Share feature is free to try.  If you find it useful you can use it any time when you are out boating for a small monthly or annual subscription via IAP.
You can get the latest version of Boat Beacon from the Apple App Store here and Google PlayStore here.
This is a step by step guide on how to configure Boat Beacon AIS Sharing with Navionics on Android (there is an iOS guide here). The AIS Sharing feature includes a free no obligation 3 day trial so you can try before you buy.
1. Launch Boat Beacon and go into Boat Beacon settings and tap “Share AIS to other Apps”. You will be offered a free three day trial with one of the two subscription period options. There is no charge if you want to cancel before the end of the trial period. Next set ‘Share AIS’ on.
You will see this prompt advising the settings to use in Navionics.
Tap OK, go back to the map view and set sailing mode on (Sailboat icon bottom left). This will position Boat Beacon on your current GPS location.  Here I am positioned in the Solent in the UK aboard the Red Kestrel. (*N.B. See notes below if there are no ships within 30 miles of your GPS location and you need to pan the map to a location away from your GPS position to see ships).

2. Now switch to the Navionics Boating app (on the same device) and position the Navionics map on your GPS position  and then tap Menu so you can configure AIS.
Scroll down to “Paired Devices”
You should then see this screen*, tap “Add Device” at the bottom.
(* If you already have a device set up you can add another by tapping the + at the top right on the device list screen.)
Fill out the Name as “Boat Beacon” ( or whatever you want to call the connection), the Host as 127.0.0.1 and the Port Number as 5353 and make sure the protocol is set as TCP.
Tap “Save” top right and go back to the map view. You should now see live AIS boat and ship icons on the Navionics map.
Now every time you run Boat Beacon in Sailing mode Navionics will automatically connect and receive the live AIS data from around your GPS location out to 30NM.
If you check back in Menu/Paired devices you will see Boat Beacon as Connected and AIS: Receiving data
Notes:
  • *If you are trying this at home far from the sea and live vessel positions you can still see AIS ship positions from Boat Beacon in Navionics but they will not get automatically updated. Pan the Boat Beacon map to a location where there are live AIS targets. Set AIS sharing on and launch Navionics and pan its map to the same location. You will see the ships’ last positions from Boat Beacon. However they will not get automatically updated. The targets in Navionics will start showing red crosses as their AIS data gets old. This is because when Boat Beacon is running in the background it can only automatically update ship positions around your GPS location. If you re-visit Boat Beacon, refresh the map and then go back to Navionics the AIS targets will all be updated again.
  • Boat Beacon must be in Sailing mode to maintain the AIS feed when it is in the background ( e.g. when you are viewing the Navionics Boating app) on your device.
  • Boat Beacon will automatically update AIS targets around your GPS location when it is running in the background.
  • You do not need to have a WiFi connection to your device to use Boat Beacon and Navionics on the same device. You must have an internet connection though (e.g. Cellular/Mobile).
  • You can share to Navionics on other devices too if they are on the same local WiFi network using the IP address shown in Boat Beacon’s AIS Sharing setting instead of 127.0.0.1 in the Navionics Devices setting.
  • If you have any questions or problems getting it working please email us at help@pocketmariner.com

How to setup Boat Beacon AIS Sharing to Navionics Boating app

Get live AIS ship positions around you on the Navionics Boating app without the need for an AIS receiver.
Boat Beacon can now share its real time AIS feed from our global AIS aerial network via NMEA with Navionics on the same device or on the same Wifi Network. Boat Beacon acts as a “Virtual AIS Receiver” and is the first and currently only app out there that offers this .
Navionics have worked closely with us on this with their Boating app  AIS feature and recommend Boat Beacon in its own category in their  Boating app – AIS Devices Compatibility Guide.
The new Boat Beacon AIS Share feature is free to try.  If you find it useful you can use it any time when you are out boating for a small monthly or annual subscription via IAP.
You can get the latest version of Boat Beacon from the Apple App Store here and Google PlayStore here.
This is a step by step guide on how to configure Boat Beacon AIS Sharing with Navionics on iOS (Android guide here). The guide uses Boat Beacon’s demo mode so you can try for free at home away from the coast and without having to purchase an AIS sharing subscription.
1. Launch Boat Beacon and go into Boat Beacon settings and turn on “Demo Mode”, then turn on AIS Sharing. It will show the default TCP port number to use 5353 and will be orange ( not connected). N.B. If you are not in the UK the demo mode will be centred on San Francisco bay in the US.
2. Tap Done top left and go back to the chart view. This will position the map on a virtual boat in the Solent ( or San Francisco Bay). All the other boats in view are real and live. Tap the sailboat icon bottom left to start sailing the demo route.
3. Now switch to the Navionics Boating app (on the same device) and position the Navionics map on the Solent ( or San Francisco Bay) and then tap Menu so you can configure AIS.
Scroll down to “Paired Devices”
You should then see this screen*, tap “Add Device” at the bottom.
(* If you already have a device set up you can add another by tapping the + at the top right on the device list screen.)
Fill out the Name as “Boat Beacon” ( or whatever you want to call the connection), the Host as 127.0.0.1 and the Port Number as 5353 and make sure the protocol is set as TCP.
Tap “Save” top right and go back to the map view. You should now see live AIS boat and ship icons on the Navionics map.
Now every time you run Boat Beacon in Sailing mode Navionics will automatically connect and receive the live AIS data from around your GPS location out to 30NM.
If you check back in Menu/Paired devices you will see Boat Beacon as Connected and AIS: Receiving data
Notes:
  • Boat Beacon must be in Sailing mode to maintain the AIS feed when it is in the background ( e.g. when you are viewing the Navionics Boating app) on your device.
  • Make sure you have Location sharing for Boat Beacon set to “Always” in your device Privacy/Location settings. Please note Boat Beacon will only use your location when it is running ( foreground) or in Sailing mode. It will not “Always” use your location – it’s just an unfortunate terminology from Apple.
  • You do not need to have a WiFi connection to your device to use Boat Beacon and Navionics on the same device. You must have an internet connection though (e.g. Cellular/Mobile).
  • You can share to Navionics on other devices too if they are on the same local WiFi network using the IP address shown in Boat Beacon’s AIS Sharing setting instead of 127.0.0.1 in the Navionics Devices setting.
  • iOS14 has introduced a new privacy permission if apps want to use local network resources which both Boat Beacon  and Navionics need to have set to yes. The OS will prompt you the first time either app tries to use a connection. You can manually set/change the permission in your device’s Settings/Privacy/Local network. See screenshot below for how we have it set.

  • Might sound obvious, but it has caught a couple of people out. You need to subscribe to the monthly or yearly AIS Sharing feature via IAP ( tap the AIS Sharing row in Settings to bring up the IAP screen) to use Boat Beacon with Navionics when not in demo mode.
  • If you have any questions or problems getting it working please email us at help@pocketmariner.com

Pocket Mariner live AIS Coverage

Our ship tracking network uses a global network of shore and ship-based radio stations, which receive signals from the AIS system that ships use to broadcast their positions as they travel. Our receiver stations share the ship positions with our cloud-based data server, which pushes them onwards and out to our apps and web services.

We are continuously working on increasing the coverage of our real-time AIS receiver station network. During the last three months we have added more than 100 new AIS stations across 5 continents bringing our live ship coverage to over 40,000 ships. We have supplied the AIS receiver for free for many of these sites. New volunteers are always welcome to join our AIS Network.

Here is a  list of the most recent stations we have set up  and a snapshot of our global coverage Q2 2019

America

Hudson Bay, NJ
Sakonnet River in Rhode Island
St Lawrence Seaway
British Columbia
Miami, Florida, US (2 new stations)
Antioch, CA.
Stockton,CA
St Bartholomew (Caribbean)
Dominian Republic.
Buenaventura, Colombia.
Lake Erie
Several stations in Uruguay
Several stations in Mexico

Europe

The whole of Norway
The whole of Denmark
The whole of Finland
Scicily, Italy
Turku, Finland
Maasbracht, Netherlands
Ijsselmeer, Nethrlands
Ust-Luga, Russia
St Petersburgh, Russia
Edinburgh, Scotland
Over 30 new stations in and around Sweden.
Eastbourne, UK
Scilly Isles, UK
Isle of Man, UK
Lowestoft, UK
Alicante, SP
Faro, Portugal

Africa

Port Harcourt, Nigeria.
Canary Islands
Dakar, Senegal

Middle East

Kuwait
Dubai

Australasia

Perth, Adelaide, Darwin, Australia
Nagoya, Osaka, Inland Seas, Japan
Singapore
Indonesia
Ho Chi Min City, Vitenam
Sihanoukville, Cambodia.

If you are interested in adding coverage for your area, please read our Cover Your Area information – we can often provide the equipment free of charge.

Real-time internet AIS Sharing to Navionics, iNavX, OpenCPN etc. with Boat Beacon

Boat Beacon can now share its real time AIS feed from our global AIS aerial network via NMEA with other apps on the same device or on the same Wifi Network. Boat Beacon acts as a “Virtual AIS Receiver” with over the horizon coverage and is the first and currently only app out there that offers this.
Boat Beacon’s global realtime AIS coverage.
 We hope this will prove popular with folks who already have other Marine Navigation apps/charts like Navionics, OpenCPN and iNavX which support an external NMEA AIS feed but don’t have their own Internet based AIS network or feed available.
Navionics have worked closely with us on this with their Boating app  AIS feature and recommend Boat Beacon in its own category in their  Boating app – AIS Devices Compatibility Guide.
The new Boat Beacon AIS Share feature is free to trial.  If you find it useful you can use it any time when you are out boating for a small monthly or annual subscription via IAP.
You can get the latest version of Boat Beacon from the Apple App Store here and Google PlayStore here.
By the way, our own top selling marine charts navigation app SeaNav already has AIS built in as standard and if you haven’t tried SeaNav why don’t you give it a spin for free first, you can download it from here now https://apps.apple.com/app/seanav/id857841271 .
Here are some screenshots from Navionics, iNavX and OpenCPN using it.

Navionics connected to Boat Beacon on 127.0.0.1 TCP port 5353

On iOS

On Android
 iNavX on same  device ( using TCP 127.0.0.1 port 5353 )

OpenCPN running on a Mac via Wifi to Boat Beacon running on an iPhone ( TCP to 192.168.1.106 port 5353).

 

There are some simple step by step instructions on how to set up Boat Beacon AIS Sharing with the Navionics Boating app here:-  https://pocketmariner.com/setup-boat-beacon-share-ais-navionics/

and here is the description in our user guide:-

AIS Sharing

Share Boat Beacon’s real time internet AIS feed via NMEA with other apps on your device and on the same Wifi network, like Navionics, OpenCPN on your Mac, iNavX etc. so you can see live ship positions around you on their charts as well. Pocket Mariner’s AIS service is fed by one of the largest network of AIS shore receivers world-wide covering most major ports, harbours and popular coastal areas with over 60,000 live ship positions at any time. Boat Beacon acts like a virtual AIS receiver and can also share your live position via Internet AIS with other users and internet based AIS services like MarineTraffic. After purchasing the Boat Beacon AIS Sharing IAP (monthly or yearly subscriptions available) just set your other apps NMEA TCP settings to connect to the IP address and TCP port (default is 5353) shown in Boat Beacon’s AIS Share setting. If you are sharing with an app on the same device you can use 127.0.0.1 as the IP address to connect to instead of the actual device IP address so you never have to change the setting when you are on a different network. Boat Beacon must be in sailing mode when sharing with other apps on the same device so it can track your position and continually update the live AIS data around you in the background. Tap the SailBoat icon  bottom left to enable Sailing mode. In the unlikely event that you need to change the TCP port number in Boat Beacon to another number, tap on the AIS Share setting row and enter it. 

On iOS you can try it out at home when there are no boats around your location by putting Boat Beacon into Demo mode ( Settings/Demo mode) first and then set sailing mode. Make sure the other app is showing the same map location as the demo mode is. Make sure to turn sailing and demo mode off when you are done. If Boat Beacon is not displaying any ships around your location then no ships will appear in the other apps either.

On Android get a 3 day free trial to try it out when you sign up for one of the subscription options. You can cancel the subscription at any time and will not be charged anything if you cancel before the end of free trial period.

Get the latest version of Boat Beacon from the App Store from here now and Google PlayStore here.

Simple 3dB dipole VHF AIS Marine Aerial from co-ax cable

Here’s how we make an AIS tuned 3dB gain VHF aerial using RF-coax cable.
Buy a 5 or 10m length of  50 ohm RF coax cable with bnc connectors already attached – this makes two – http://www.amazon.co.uk/dp/B00JVUP0L4. Cut to required length. Strip back the outer coating at the cut end to a length of 44.4cm + 5cm to make a loop (1/4wave for AIS frequencies). Pull the inner core through the outer sheath and lay the outer sheath back along the length of the coax and trim to 44.4cm. I add a couple of cm to the length so I can bend the tip of the inner core back on itself to hook it over something. Make sure the length of the inner is 44.4cm excluding the looped over end. Cover in heat shrink wrap if you want to make it waterproof and you have a 3dB gain AIS Aerial.
There is a useful video here showing how to do it here :-
and a photo of a 5m long one we made earlier. This one had a range of over 25NM when we put it on the 20th floor of a high rise in Singapore.
Screen Shot 2016-04-08 at 15.07.39

You could also go one step further and make a 6dB  collinear like this from Neil Arundale (I have made and used one of these too and it compared equally with a £120 commercial collinear).

I hope that this inspires someone. If you get connected up please consider sharing your AIS data with us. We can provide a dedicated port and web view for your data.

Alexa Boat Beacon skill – talk with your boat

Boat Beacon now works with the amazing Amazon Alexa and Echo devices using our free Alexa Boat Beacon skill.

“Alexa, ask Boat Beacon my position”

“Sarita is travelling North East at 6 Knots in the English channel currently 5 miles south west of Plymouth”.

Or ask for “exact position” and hear : “Sarita. Latitude 52 degrees 1 minute North, Longitude 1 degree 52 minutes 34 seconds West, course 55 degrees true, speed 5 Knots.”

You can see a short 19s video clip of the Boat Beacon Alexa skill in action here :-http://boatbeaconapp.com/BoatBeaconAlexa.mp4

Just ask Alexa to register your Boat Beacon 9 digit BBSI number (without the BB prefix) to associate the Alexa Boat Beacon skill with your own Boat Beacon app and put Boat Beacon in transmit mode (sailing)  to update your location, speed and course in real time.

“Alexa, ask Boat Beacon to register 617648992”

Response: “Boat Beacon BBSI 617648992 has been successfully registered. You may now ask for its position”.

You can find your unique Boat Beacon BBSI number at the bottom of Settings/My Boat Details in the Boat Beacon app on your iPhone or Android device. See the iPhone screenshot below.

Friends and family can also use the Boat Beacon Alexa skill to follow your progress  when you share your Boat Beacon BBSI 9 digit number with them.

We have lots of other ideas up our sleeves for the Alexa Boat Beacon skill if it proves popular. “Alexa, ask Boat Beacon to alert me on CPA” , “Alexa, ask Boat Beacon to tell me if the wind exceeds 6 knots” and would love to hear your ideas. And if you want to know where another boat is by name or MMSI number you can use our free Boat Watch Alexa skill

Get the free Boat Beacon Alexa skill here now:-

https://www.amazon.com/gp/product/B07BDN2W6X

How to find your BBSI number

Open settings in Boat Beacon on your iOS or Android device, select My Boat Details and scroll down to the bottom to see your Boat Beacon Id  (BBSI). Use the 9 digit number (without the BB letters ) to connect Alexa with your iOS or Android device.

 

Latest Global AIS Coverage map

Here is the latest snapshot of our worldwide AIS coverage broken down into 0.25 degree squares. Zoom in to see the detail. We have recently added coverage for the whole of Finland, Norway and Denmark, the Black and Red Seas, Istanbul, The Suez canal and the Panama canal (East) and mucg improved coverage around the UK and IE. We are now showing over 50,000 live ship positions per hour; amongst the best in the industry. We only use real time data. We do not use satellite data which can be several hours behind real item like some other AIS services do.

We also record all the AIS messages and store them for ever. We have global time stamped AIS data going back to 2014. If you would like to use our live or historic AIS data please contact us at support@pocketmariner.com

 

Augmented Reality with FLIRONE

Augmented Reality with FLIR ONE

MORNING_CALM_BB_AR_FLIR_IOSPocket Mariner collaborated with Practical Boat Owner to successfully complete a demanding night time sea trial of our popular marine navigation apps, SeaNav HD and Boat Beacon with the  FLIR ONE Thermal Imager for iOS; a new, low cost , infra-red thermal imaging camera for the iPhone.  The FLIR ONE makes thermal imaging affordable and accessible to a much wider audience at a fraction of the cost of the higher end marine IR imaging devices. Pocket Mariner have ingeniously integrated the live thermal image with their widely acclaimed iOS Augmented Reality mode providing identification, distance and bearing of the ships and Aids To Navigation in view at night and in fog.  We wanted to see how well and how far off we could spot ships via their infra-red signature and if the FLIR ONE could help with searching for a Man Overboard (MOB).

Practical Boat Owner, the UK’s leading boating magazine, bravely deployed their editors, David Pugh and Ben Meakin, together with Ben’s Impala 28 yacht , “Polly” and intrepid “Woman Overboard” volunteer, Laura, along with Pocket Mariner’s CEO, Steve, on a pitch black night in Southampton water.

Here’s what we saw.

Continue reading “Augmented Reality with FLIRONE”

Quark-Elec AIS receiver review and Boat Beacon

For inshore (less than 10NM from the coast) our real-time internet AIS service for Boat Beacon and SeaNav has a lot of advantages over VHF AIS receivers and reception, it is very cheap, easy to install (no aerial required), easy to use and provides incredible range including “seeing” round corners and over headlands and islands. However if you venture further afield and go out of range of internet coverage, for instance when half way across the English channel between Southampton and Cherbourg and in the main shipping channel you need a VHF AIS receiver!

Many of our Boat Beacon and SeaNav users use our apps both for internet AIS and as a display and CPA alert device for their on-board VHF AIS receiver. There is a new and relatively inexpensive range of AIS receivers out on the market from Quark-Elec and also the dAISy. They are less than a quarter of the price of the usual AIS receivers from the likes of Digital Yacht, Comar and Weatherdock etc. . We wanted to try them out for use with SeaNav and Boat Beacon on iPad and iPhone.

iOS does not support USB connections so to get local AIS data into your iPad you need to connect via Wifi and will need an AIS receiver with Wifi built in or get a USB to Wifi adaptor. There are no USB to to wifi adaptors available on the market! It is possible to build your own for around £50 using a Raspberry Pi or BeagleBone Black as we have done but for this comparison this rules out USB only AIS receivers such as the dAISy unfortunately.

We drove out to nearby Dial hill in Clevedon overlooking the Bristol Channel at a height of approximately 100m above sea level. At this height the VHF horizon should be around 32NM for spotting ships. We used a standard marine 1/4 wave whip  AIS aerial (£50) on a tripod and our SeaNav app on a laptop in the car to run a comparison test to see how the Quark-elec compared to the Digital Yacht AIS receivers that we normally use.

ais_tests

and the view

IMG_1487

First off the devices:-

The dual channel Digital Yacht AIS wireless receiver at around £365.  http://www.cactusnav.com/digital-yacht-iais-wireless-receiver-p-11569.html. This also allows you to attach other NMEA data such as wind, speed and depth etc. to your iPad via the Wifi channel.

iais web
The Quark-elec A026 Wifi enabled AIS and GPS receiver at £94.79 . http://quark-elec.com/products/marine/147-qk-a026

A026_System_diagram

This looks like an amazing device as it also includes a GPS receiver and a NMEA multiplexer so you can combine data from Wind instruments, Speed log and Depth over Wifi too. You can get one without GPS for £79 – the QKA-024. So price for price this is less than a quarter of the price of the Digital Yacht equivalent!

The results

Quark-elec A-026

QuarkA026Screen Shot 2017-05-06 at 11.06.38

Digital Yacht iAIS

(note all the ships around Hinkley point near Burnham-on-Sea to the south, busy helping with the build of the new Nuclear reactor there).

DYScreen Shot 2017-05-06 at 11.01.47

The Quark picked up ships out to around 20NM from our location. It did not pick up the weaker Class B transmissions  from about 11NM away (purple boat in Cardiff and orange boats in Barry and Hinkley point in the Digital Yacht screenshot). The Digital Yacht maximum range was 39NM just over the expected VHF horizon.

Conclusion

The DY device was far more sensitive than the Quark with nearly double the range for picking up large ships using Class A AIS (12.5W). Class B AIS is much lower power than the class A that ships use and at only 2.5W has a maximum power limited range of around 8-10NM which appeared to be within the Digital Yacht’s capabilities but just beyond the Quark’s.

If you are on a small boat and your AIS aerial is at most 10m above sea level the VHF ship spotting horizon range will be about 12NM (see note at end on calculating VHF horizon range). The Quark easily met that target for spotting ships. With the built in GPS version you can provide GPS to your Wifi only iPAD too. The Quark-Elec A026 would be a great buy on that basis if you want to use it on your boat with SeaNav so you can pick up AIS when out of range of our live internet coverage, for instance when half way across the English channel between Southampton and Cherbourg.

By the way, you don’t have to buy and install an additional aerial to get VHF AIS on your boat, you can share your existing marine band VHF radio aerial via a lossless splitter like this one from Glomex:-http://www.marinesuperstore.com/marine-communication/vhf-antennas/glomex-ais-am-fm-splitter-ra201ais

At Pocket Mariner we are also interested in using AIS receivers for our real time global AIS shore based AIS network which we are continually growing, now picking up live positions from over 40,000 ships around the world at any one time with  several hundred AIS receivers and aerials. Although the price point of the Quark is tempting, when you factor in the costs of installing and connecting up an aerial, the 4 fold increase in coverage area the Digital Yacht devices give us wins for shore based AIS stations.

VHF Horizon

VHF travels in a straight line and its range is limited by the curvature of the earth. The higher the aerial is placed above sea level the further it will see. A simple rule of thumb for calculating the range of an aerial is the square root of its height above sea-level in feet in NMs. So an aerial at 25′ will have a range of 5NM. To get the range that you can pick up targets at you need to combine the range of your aerial and that of the target. So for aerials both at 25′ the range will be just over 10NM. If you prefer metric, take the square root of the height above sea level in meters and then double it to get range in NM. e.g. 9m gives approx 6NM range. An AIS aerial mounted at deck/guard rail  level will only see large ships to about 8NM out!

http://www.literasea.ca/radar-horizon.html

vhfhorizon