Two weather-subscription packages are available: The Marine Coastal (Mariner) package includes weather buoy observations and sea-surface temperature, as well as a wind and wave forecast, city forecasts, and current fuel prices. The Marine Offshore (Voyager) package includes the same features, with an enhanced wind- and wave-forecast window of 48 hours.
“We offer most of the SiriusXM data sets,” says Hogan. “We also have new software coming out for NSE and NSS that supports even more.”
Furuno also supports a couple of options, and some things you find nowhere else. The Sirius weather receiver BBWX2 ($800) works with NavNet TZtouch, NavNet 3D and NavNet vx2. Additionally, NavNet TZtouch supports the free Marine Weather Forecast at navcenter.com, which downloads files directly onto the plotter. Select an area, then zoom in to reduce the coverage of the downloaded GRIB files, while increasing the area detail. “It’s delivered in a tiny file that goes graphic on the display,” says Eric Kunz, Furuno’s senior product manager. “You can peel the layers you unpack to and show what you want to see. “
Data layers include wind, waves, atmospheric pressure, clouds, rain, sea-surface temperature and ocean currents, and a couple that are seldom available elsewhere: chlorophyll and altimetry. Chlorophyll identifies nutrient-rich areas of the sea surface that are likely to support an active food chain, from plankton to predators. That’s valuable information when you are hunting predators.
The second data category, altimetry, provides the height of the sea surface above or below mean sea level. Variance in sea-surface height is a function of temperature in the water column. Warm water occupies more space than cooler water, which raises the sea surface. This variance can be measured by satellite and plotted on a chart to indicate water-column temperature. Altimetry indicates water temperature at depth to locate temperature breaks far below the surface, independent of sea-surface temperature, which is affected by cloud cover.
Altimetry data is little utilized and seldom discussed. “The big thing about altimetry,” says Kunz, “is the guys who know about it don’t want to talk. Our engineers don’t want to talk about it because they don’t want to educate the competition. There are anglers on the East Coast who have used it to win major tournaments, and they don’t want to share their edge. Knowledge, in this case, is power.”