AntennaPilot

AntennaPilot

How to show the ship's position on cabin TVs and crew screens

From the bridge NMEA data to cabin TVs, kiosks and crew PCs: which data you need, how to take it from the bridge network safely, and how to put it on screen.

"Where are we now?" is one of the questions guests ask most on an expedition ship. A map channel on the cabin TV answers it for everyone at once. Building one needs three things: position data from the bridge, a server that draws the map, and a way to put the page on the screens, without opening a path into the navigation network.

The data you need

Bridge equipment talks NMEA 0183 (IEC 61162-1), usually on serial lines, and on newer ships also IEC 61162-450, which is NMEA over UDP multicast on Ethernet. For a position display these sentences are enough:

  • GGA or RMC: position, time and fix quality;
  • VTG: course and speed over ground;
  • HDT: true heading from the gyro;
  • ZDA: date and UTC time;
  • optionally DPT or DBT for depth and MWV for wind.

Take the data one way only

The navigation network must not be reachable from the hotel or crew networks. Take a copy of the NMEA data from a spare output of the bridge multiplexer, or through a serial-to-Ethernet converter that only sends. A read-only, one-way feed means a problem on the entertainment side can never reach the ECDIS or the autopilot. For ships contracted for construction on or after 1 July 2024, the IACS unified requirements E26 and E27 on cyber resilience also apply, and the classification society will look at how the networks on board are protected.

Putting the map on the screens

  • Cabin TVs. Many IPTV systems can show a web page as a channel, or take an HDMI encoder fed by a small PC running the map full screen. Use large text: position, time, speed and course must be readable from the bed.
  • Kiosks and crew PCs. A browser in full screen mode pointing at the map server on the ship's network.
  • Phones. The same page on the guest Wi-Fi, if the network rules allow it.

Keep satellite traffic low

A map that downloads its tiles from the internet on every screen will use the satellite link all day. Keep the tiles on the server on board, and download weather data once for all screens, not once per screen. Show the age of the data, so nobody takes a six-hour-old forecast for a current one.

Agree it with the bridge

The master decides what the passengers see. In some areas the ship security plan may require that the position is not shown on public screens. Make sure the channel can be switched off quickly, and agree with the bridge who does it.

Doing it with Wakeline

Wakeline reads the bridge NMEA data, read-only, and serves a live chart with the ship's wake, weather, tropical cyclone and navigational warning layers to cabin TVs, kiosks, crew PCs and phones on the ship's network. The map tiles are kept on the server on board, and the same server gives the whole network accurate time from the GPS. Wakeline is installed for each ship; ask for a quote.

All shipboard IT guides · Razvan Malciu, shipboard IT officer