All the instruments and navigation data used by our Ambassador Erwan Le Lann, Captain of Maewan association's sailboat

Whether you want to prepare an outing at sea or manage your navigation onboard, it is crucial to always have access to your navigation data.

TZ Navigator offers a comfortable user experience by allowing navigators to display or hide all the information necessary for safe sailing. Thanks to NMEA 0183 and 2000 compatibility, you can easily connect your navigation hardware: radar, AIS receiver, GPS, etc. Additionally, the advanced compatibility of Furuno instruments facilitates this integration.

Erwan Le Lann has been a TIMEZERO ambassador for many years and uses TZ Navigator v4 onboard of the “Maewan” for his trips. Exploring the waters of the Pacific, Erwan has a very particular navigation style. In fact, he spends a lot of time sailing close to the coast to fulfill his educational and environmental expeditions. He therefore optimized his onboard solution to have constant access to his tools and data.

In this article, our partner explains with great precision the various instruments he uses to prepare and manage his trips. Later in this article, Erwan shows us all the necessary navigation data used to ensure the best safety conditions for his crew.

The navigation instrument onboard the “Maewan”:

The GPS connected to the AIS receiver:

The GPS allows for the localization of “Maewan” and therefore for the display of the boat directly on the navigation chart in the TZ Navigator software: “We have a GPS connected to an AIS receiver that positions “Maewan”. It emits our position and receives the position of nearby boats (less than 24 nautical miles). The AIS is an essential tool to detect, be detected and place the boats that cross our path. Even if certain boats aren’t equipped with a GPS, all large ships are obligated to do so. The AIS and GPS are also used to give the course, the speed and the position coordinates. The software is also connected to the radio, this way, if needed, the distress signal can be triggered on the radio and our GPS coordinates will be shared.”

The satellite antenna:

To constantly have access to the Internet and a phone line, “Maewan” is equipped with a satellite antenna. Despite the high price of data, it is thanks to this connection that crew members are able to communicate with people on land by sending texts and photos. However, this antenna is especially used to download GRIB files using the Squid, The Great Circle software. Using this downloaded data, Erwan can prepare his trips in advance: “We have 10 days of weather forecasts with the direction and strength of the wind but also the clouds, rain, wind gusts, waves and the swell. All this information is imported in TZ Navigator, and, this allows us to have an adapted interface for each piece of data. All the marine charts are loaded onto the software and the iPad app TZ iBoat serves as an additional complementary tool.

The autopilot and the NKE display:

“The autopilot is autonomous and separated from the navigation instruments onboard the “Maewan”. It is composed of a compass, an electrical navigation system, a pump and a hydraulic cylinder connected to the rudder. The NKE display allows to set the course of the boat along with the outside repeater screen and the remote. We have access to the boat’s course everywhere on the deck! Depending on the state of the sea and the strength and direction of the wind, the pilot adjusts his reactivity and principally the amplitude of his movements. He gives us information related to the helm and, when we interpret this information, they allow us to know if the sails are well positioned or if we need to adjust them. Plugged into the navigation system, we also have a rudder feedback sensor. This too is vital to the operation of the autopilot as it informs the system of the position of the rudder. Without this element, the autopilot would be lost since it wouldn’t know the helm’s position.”

The water depth sensor:

Directly plugged into the NKE display of the autopilot, the water depth sensor is vital for Erwan and his crew. When navigating close to the coast, they often have to protect the “Maewan” even in unusual locations. Displaying the depth data up to 100 meters, this sensor gives Erwan the ability to explore places nobody would dare to with this sailboat.

Navigation data:

In TZ Navigator, the right part of the screen is entirely dedicated to the display of navigation data, also called NavData. Using NavData, you can display and hide necessary information depending on the instruments connected to your PC but also depending on your preferences. Below, Erwan tells us about the 7 pieces of navigation data that are always within sight!

  • Date and time:

“The displayed time is the Greenwich Universal Time UTC. It is the reference time for navigation since weather data is synched to UTC time. Additionally, it is the only valid hour at sea as we cross time zones and there are no borders.”

  • Cursor position

“Depending on the position of the mouse cursor, GPS coordinates, the course between the boat and the cursor, the distance in nautical miles and the time needed to reach this point that adjusts according to the speed of the boat.”

  • SOG (Speed Over Ground)

“The Speed Over Ground is the speed of the boat in relation to the ground (calculated using the GPS). It varies depending on the currents and the speed of the boat in relation to the surface or the bottom. Here we navigate at a speed of 4.7 knots. 1 knot = 1 nautical mile per hour and 1 nautical mile = 1.8 kilometers (approx.), so we are going at 8.5 kilometers per hour.

  • TWS (True Wind Speed)

. This data gives us “true wind speed and not the one felt on the boat that is composed of the true wind speed and the speed and angle of the boat in relation to the wind.”

  • AWA (Apparent Wind Angle)

“AWA is the angle of the wind in relation to the boat, here B73.0° means Port side 73°(Bâbord in French), if the wind was coming from the Starboard side, there would be a T (Tribord in French). This indication is important when it comes to noticing changes In the wind and adjusting the sails accordingly.”

  • COG (Course Over Ground)

“COG is the course in relation to the ground and is calculated with the GPS. I am regularly comparing this value with the course of the compass of the autopilot as well as the magnetic course, to get an idea of the drift we are experiencing.

  • Weather information

“The weather information is related to the imported weather data file and to the position of the mouse cursor. We are able to see the direction and force of the wind. Depending on what we download when gathering weather data, we can have pressure, swell, waves, wind gusts etc.”

TZ Navigator v4 is a very comprehensive software that gathers all the tools and necessary data to manage your navigation with the greatest level of safety. Whether for coastal or transatlantic navigation, TZ Navigator was developed to answer all your needs, including those of the most demanding sailors.

If you want to follow the adventures of the Maewan Association and of Erwan and his team of explorers, visit the official Facebook page:

Thanks to GPS position of the boat, you can also follow every move of the “Maewan” live and online with Marine Traffic (boat name: Maewan 4):

For more information on TZ Navigator, the recreational navigation software, we invite you to visit our free tutorial page: