TCP Connection Problems on Apple iOS 10


Since Apple’s release of iOS 10 for iPhones and iPads, we have been getting a number of calls and emails saying that various navigational Apps that read wireless NMEA data from our products have stopped working, including our free iAIS app.

There are two modes/protocols that our wireless NMEA products can work in; TCP which is a reliable one to one type connection supported by most apps and UDP which is a broadcast protocol that allows multiple devices to all receive the same data.

When we started to investigate, we found that TCP communication on all Apps no longer worked with iOS 10 and UDP only worked on some apps. At first we thought this might have been an Apple API type change that had caused the problem, but then we discovered that changing the IP address of our wireless NMEA products from to fixed the problem.

The IP address range is usually reserved for Ad-Hoc networks where there is no DHCP server and dates back to our first iAIS product (released in 2011) that only supported Ad-Hoc networks. With the release of Android, which did not support Ad-Hoc networks, we updated our wireless NMEA products to the more common Access Point mode but retained the IP address, to avoid changing too many Apps and Documentation.

Now it seems that Apple are clamping down on TCP connections on Ad-Hoc networks and this means that all customers who have updated their iPhone or iPad to iOS 10, will need to change the IP address of their wireless NMEA product, if they have one of our; iAIS, WLN10, WLN10HS, WLN20, NavLink, PilotLink or AIT3000 units. Please note that our iNavHub and Sonar Server products are not affected by the iOS change.

To make this procedure as easy and simple as possible, we have created a new Tech Note that explains what needs to be done. Click here to download.


SailRacer App now with Charts on Android and iOS


When we updated our Android Apps listing last month, we were given some advanced information that SailRacer the popular tactical yacht racing app, was soon to be getting a major upgrade to support navigational charts. True to their word, this week new Android and iOS versions of SailRacer will be released that allow users to overlay all of their race marks, layline and wind information on a navigational chart.

Of particular interest is the new chart upload feature that allows you to scan or take a photo of a paper chart of the race location and to then quickly align the chart with your precise race marks using the powerful “map center” feature. Traditionally SailRacer has plotted the racing marks on a blank track plotter type screen, but now with the addition of nautical charts, a whole new layer of essential local geographical detail is available to give you the edge in your tactical decision making.

The new Apps will be available from the Google Play or the Apple App Store later this week or you can visit to learn more. An interesting video to show how you upload your own charts to Sail Racer can be seen here.

Both apps are compatible with Digital Yacht’s wireless NMEA servers.

New update for NavLink App for iPhones/iPads


We are pleased to announce a new update is now available for our popular NavLink UK and NavLink US apps for iPhones/iPads. The update which existing users can get free of charge from the App store provides the following new features;

–  External NMEA GPS support – great for iPads without built-in GPS (also supports GPS from AIS transponder).
–  Rate of turn vectors showing bending ship course prediction.
–  Relative scale ship icons – so big ships appear bigger.
–  Ship names displayed on map – so you can see the ships’ names without having to tap on them.
–  Ships drawn at true scale size when zoomed in on the map – vital for seeing the size of the gap or passage around large vessels.

Our NavLink apps which work with all of our wireless NMEA servers are perfect for anyone that wants to wirelessly receive AIS and GPS data from their boat’s AIS system. For more information click on the links below.

NavLink UK which includes UKHO vector charts for UK+Ireland and optional in-app purchase for other North European charts.

NavLink US which includes NOAA vector charts for the US

If you do not already have an AIS but want to get one with this wireless capability, please look at our iAIS (receiver) or our brand new AIT3000 (transponder with splitter) products.

Connecting an AIS Receiver to an Android Tablet with Boat Beacon

Android Tablet

Today we finished a series of successful tests, connecting our AIS receivers to a Google Nexus 7 Android tablet. This was made possible by a new version of Boat Beacon the popular AIS App for Apple and Android devices, which should soon be available (as a free update) on the Apple Store and Google Play Store.

One of the most popular features of Boat Beacon was that it allowed you to receive AIS data on your phone or tablet (from the internet) without having to install an AIS receiver on your boat. What is more, you could also transmit your position (without having an AIS transponder), so that you appeared on AIS websites like Marine Traffic, Ship Finder and AIS Hub, allowing friends and family to track your passage. In order to receive AIS data and transmit your position, you needed to have a 3G internet connection, but for many people Boat Beacon was a great app to have and introduced them to the world of AIS.

Relying solely on Internet AIS data does have serious limitations though, namely;

  • Holes in the AIS network coverage
  • Slow update speeds
  • Constant risk of losing the 3G internet connection

This is the reason why most boat owners ultimately decide to fit an AIS receiver on their boat, but then you have the issue of getting this AIS data on to your phone/tablet. With Apple devices, currently the only option is to use one of our Wireless NMEA units to convert the AIS data in to wireless NMEA data that an App running on the iPhone/iPad can read. Many Apps including Boat Beacon support Wireless NMEA, which we documented in a recent article (click here to read it).

However, many Android devices now support USB “On the Go” (OTG) which allows USB slave devices to be plugged in – see USB OTG cable in image above. In order for the USB slave device to work correctly, Android must have suitable drivers installed and there must be an App running that knows how to use the USB device. As part of our testing, we confirmed that the drivers for all of our AIS receivers (and our NMEA to USB adaptor cable) are pre-installed in Android and that the latest Boat Beacon App will read the NMEA0183 AIS data and display the AIS targets on its chart display.

Installation could not be easier, simply plug in the USB OTG cable to your Android device, download the latest version of Boat Beacon and then plug the USB lead of one of our AIS Receivers in to the OTG cable. Android should detect the AIS device and ask you to confirm that you want Boat Beacon to use this device.


Then Boat Beacon should open and you should see the live AIS data starting to come in and be displayed on Boat Beacon.


With CPA and TCPA alarms, colour coded AIS targets and the facility to also transmit your position back to the internet AIS sites via 3G, Boat Beacon is the best AIS App for Android and now with the option of connecting our AIS receivers via USB or any of our AIS units via one of our Wireless NMEA adaptors (WLN10, NavLink, iNavHub, etc.) you have an app that can be seriously used at sea as an AIS display and alarm system.

For more information on Boat Beacon visit the Play Store by clicking here.