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Driven by the profound desire to make your sailing a genuine source of pleasure and excitement, it’s essential for us to offer you the best and make this pleasure accessible to all.

We have chosen to work with Garmin, the world leader in GPS equipment, for the nav instruments aboard our boats. In addition to enabling efficient, comfortable and safe navigation, new technologies today offer a host of additional, modular options that can be adapted on board.

Technology is great, but it’s even better when you know how to use it. In this article, we take a look at how the Excess system works, how it performs and what extension options there are.


A boat’s electronics consist of several sensors, connected to each other via a bus called the “NMEA 2000 network”, which transfers data to the navigation display.        

At Excess, the electronics system installed on our boats includes:

  • Navigation sensors: consisting of an electronic wind vane (gWind Wired) at the masthead, giving wind direction and strength, and a tri-function sounder (DST810) beneath the hull, giving depth, sea surface temperature and speed through the water.
  • Gauge senders installed in the tanks transmit levels for on-board autonomy, while battery sensors transmit the boat’s voltage and enable alarm management.
  • An autopilot (Reactor 40) and a hydraulic ram (LS40 from Lecomble & Schmitt) are also part of the initial Excess configuration.


Various instruments, receivers and displays can be added to these: the chartplotter (GPSMAP) allows you to position yourself on a base chart, the radar allows you to spot obstacles to navigation, the VHF and AIS allow you to communicate with other craft in the vicinity...

All these elements are regularly chosen by our customers and offer a wide range of induced functionalities that cover the majority of their needs for offshore sailing.


The multifunction display (GPSMAP), equipped with a powerful processor that collects data from the various sensors/receivers, cross-references them and produces additional information derived from calculations, such as true wind speed, true wind angle or leeway. All this information is retransmitted to the boat’s displays.


All these electronic elements, in addition to being a perfect navigation aid for skippers and their strategic choices, will also serve as a command generator for the autopilot. Upstream data processing will enable you to navigate under autopilot in the following modes: heading hold, track following or wind holding. Once the boat is set to its best point of sail, you can engage the wind mode (true or apparent), and the autopilot will maintain the requested wind angle, enabling you to sail at the desired speed. The autopilot is an indispensable option for long passages, provided you keep an eye on its course-keeping. From the control station, you can adjust the pilot’s sensitivity according to sea conditions and response time.

A particularly intuitive feature with the Garmin interface is the choice between true and apparent wind mode, and this is a major advantage on a catamaran: when sailing upwind, the apparent wind mode allows the boat to take advantage of every little breeze. Conversely, downwind, where the boat’s accelerations make the apparent wind very unstable, true wind mode will keep the boat on a much steadier course.


Thanks to an intuitive, customizable user interface, it’s easy to organize your own dashboard and select a multitude of options for displaying all data.


High-performance navigation software:

Garmin has developed specific functions for sailing that are particularly precise and efficient. Known as “Sail Assist”, these functions enable you to optimize your settings and sail in the best possible conditions. The gWind wired windvane, for example, records wind speed and direction over a given period of time, perfect for analyzing wind trends while sailing. You can also determine the boat’s leeway by calculating the difference between the log (speed through the water) and speed over the ground from the GPS.


By collecting and calculating all the data received by the various receivers & transmitters, the navigation computer will, for a saved route, use laylines to indicate your VMG (Velocity Made Good), i.e. the best course to follow based on the course/speed compromise to reach your destination as quickly as possible.


For even greater precision, it is also possible to enter the boat’s polars to measure your actual performance against your boat’s theoretical performance. And lastly, racing sailors will be able to take advantage of start line assistance to cross the line at the right moment and at full speed!


Detailed, crowd-sourced cartography:

One of Garmin’s many strengths also lies in its cartography. Owned by Navionics for many years, the BlueChart g3 navigation charts (supplied by Excess with the GPS display) are enriched with Navionics cartographic data for even safer and better navigation.

BlueChart cartography provides access to navigation charts with all information such as buoyage, light sectors, soundings, regulated areas; as well as detailed fishing charts which model the seabed with bathymetric contours. These charts are extremely useful for fishermen and divers, as well as for analyzing an upcoming anchorage.


Garmin Navionics+ charts are available as an option. This new generation of charts offers new features such as :

  • A new color palette,
  • Daily chart data updates,
  • AutoGuidance+ “Dock to Dock” technology

But also, Bathymetric contours displayed every 50 cm, depth shading functions and access to the ActiveCaptain community.


These electronic nautical charts also incorporate crowdsourced data, based on the experience of all Navionics users.

The “Dock to dock” Autoguidance+ technology automatically calculates the best route to your destination, based on your boat’s size, cartographic data and other users’ most frequented routes. In this way, the route is not calculated solely on the basis of buoyage, but also takes into account the routes most frequently used by other boaters. This can be a useful option in channels, in areas of high tidal range or even in areas that are less frequented.


Similarly, Garmin Navionics+ lets you download bathymetric charts generated and completed by the community, view popular points of interest, and access recommendations and tips from boaters who have local knowledge of the area you plan to explore. All these features enable you to take advantage of the navigational habits of the world’s largest boating community!


Connected, flexible and evolving navigation:

To perfect the notion of comfort, Garmin has developed its own mobile app. Called “ActiveCaptain”, this free app links your smartphone/tablet to your chartplotter. At home, you can download chart/software updates, create routes or search for the best anchorages rated by the community. Once on board, the mobile device automatically synchronizes with the chartplotter to export downloaded data to your navigation screen. And thanks to the Helm function, you can duplicate the display of your multifunction screen on your smartphone or tablet.


To sum up, the Garmin electronic packages offered by Excess provide a host of intuitive and fun-to-use functions, and cover a wide range of needs, including for use offshore. Your basic installation can be supplemented by other elements, such as:


Radar. The GMR Fantom 18x is a solid-state radar featuring MotionScope™ technology. This technology uses the Doppler effect to detect moving targets and highlight nearby vessels or weather cells, using different colors. In addition, this radar offers numerous features to maximize safety on the water such as the ability to set up a virtual guard zone, dual watch which allows you to monitor the body of water at two different range scales, automatic MARPA target acquisition, radar echo display and more.

Finally, this radar offers advanced settings to reduce its power consumption by adjusting its transmitting power or programming the transmitting time.


Another available option: Garmin’s Quatix 7 smartwatch is a real plus. It displays navigation data such as speed, wind direction and depth directly on your wrist. It can also be used to control your audio system or autopilot, or to display additional information at sea, such as barometric pressure or air temperature. Like most connected watches, information on your state of health is also available: it analyzes sleep patterns, heart rate and more, which can be of useful interest for single-handed sailors, for example.


Let’s take a look at the second point of interest of the on-board electronics network: safety. With the standard packages offered on delivery and a few optional extras, you’ll have all the equipment you need to ensure complete safety and easy communication.


For communications, the VHF 315i is the essential element on board. This “black box” VHF offers 25W transmit power and a built-in GPS receiver, enabling you to benefit from the DSC function. In the event of a distress call, the boat’s position is automatically transmitted to all stations. 


The AIS 800 transponder is an AIS transmitter/receiver. It transmits information about your boat to other AIS receivers in your vicinity, while receiving data from surrounding AIS targets. By selecting an AIS target from your Garmin multifunction display, you’ll have access to its identity, course, speed, distance to the closest point of approach and time remaining until arrival at that point. An adjustable collision alarm alerts you to dangerous situations.


For even greater safety, you can also add an InReach satellite communicator to your system. This is a portable beacon that enables you to communicate with your loved ones ashore, or with emergency services, by means of a service subscription. Depending on the model purchased, you’ll be able to display chart data, access weather information and connect the communicator to your Garmin watch.


To summarize, the standard Garmin electronics package from Excess is particularly comprehensive, intuitive and high-performance for navigation. The range of products on offer is precisely tailored to your various communication and safety needs. What’s more, the Garmin architecture is highly scalable, thanks to its NMEA 2000 compatibility and connectivity solutions. This wide range of customization options for on-board electronics is a major asset for the most demanding users.

We are, for example, awaiting the release of the electronic telltales for trim control developed by Garmin, then tested and approved by one of France’s top racing skippers, Michel Desjoyaux. By adding sensors to the sails, you’ll soon have on-screen access to analysis of the airflow over the sail, for perfect sail trimming, even at night!...

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