The new overlay combines the sea chart and weather chart in one display. All weather parameters important for navigation are presented as values or symbols on a separate layer and can be switched on and off at any time.
The system can show all available weather forecasts for the next few days, which can also be played as an animation.
The parameters which can be displayed include the mean wind with direction and speed as well as gusts, wave height, wave direction and swell, period intervals of waves and swell, current, air pressure, weather conditions and air temperature.
The navigator can define which data they want to have displayed in a particular situation, and which limits they would like to set. If individual weather values exceed the pre-set limits, the values are shown graphically as weather warnings.
“The consideration of weather data is becoming more and more important for the shipping industry,” says Thomas Wolter, product manager at Raytheon Anschütz.
“Wind and waves or weather conditions such as fog have a direct influence on safety. Wind and waves, swell and currents have a direct influence on fuel consumption. And all together influence the travel speed and prompt arrival at the destination harbour.
“The Gulf- or Canary Streams move at about 1 to 1.5 knots, or 24 to 36 sm per day. Even at a relatively slight decrease in its own speed, the engine requires significantly less fuel, which at today's bunker prices has a great effect on the cost. For a 15-year-old, 20,000 dwt container ship with a speed of 20 knots, a speed change of one knot can make a difference of about 10 tons of fuel per day.”
The Synapsis ECDIS imports the weather data via a standardised GRIB-file from a weather data provider. Customers can choose themselves from which provider the data are to be taken.
Free weather subscriptions are available which offer some basic parameters, but sea weather reports from professional weather service providers are also available.
The paid data packages contain complete sea weather information and range in size from 25kb for the Baltic Sea to 500kb for the complete North Atlantic. The data can be imported into the ECDIS by download or e-mail, either directly or via a USB stick.
Raytheon notes that free weather data usually contains less information, but at the same time much larger amounts of data.