Article by Capt. Steve Katz
Shaded Relief
Choosing the best electronic chart for your fishing area is no easy task.
One area of boating accessories that has become much more competitive with new offerings is electronic navigation and fishing charts.
For those who don’t know, many of the independent marine charting companies have been bought up by the major marine electronics manufacturers over the last few years, with not many benefits to the boaters until recently. Garmin, who purchased Navionics in October 2017, has been diligently working to revamp their cartography ever since. C-Map is now owned by Navico (the Owner of Simrad, Lowrance and B&G). Nobeltec was purchased by Jeppesen, a subsidiary of Boeing, sold again and is now marketed as Timezero and the new entity is partially owned by Furuno. Let’s not forget about free NOAA Electronic Navigational Charts (ENC), these are vector charts, they are available in S-57 format though are not often directly compatible with your chartplotter.
The most desired new feature sought after by anglers is the shaded relief charts. This is a highly detailed view of the bottom, almost lifelike. Much of the data for the detailed bottom contours is derived from LIDAR. LIDAR is an acronym for Light Detection and Ranging, which is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth from an aircraft. These light pulses—combined with other data recorded by the airborne system— generate precise, three-dimensional information about the shape of the Earth both above and below the water. The Bathymetric LIDAR uses water-penetrating green light to measure seafloor and riverbed elevations. In our area, the amazing bottom detail from LIDAR is available for the near shore area out to about 20 miles.
So, what about my chart plotter – what charts can I use?
Garmin
The Garmin chartplotter displays are only compatible with Garmin branded cartography. Whereas Simrad, Lowrance, Furuno and Raymarine often have the ability to use third party charts along with the manufactures own brand of charts. The chart compatibility may depend on both your chart plotter model and software version.
The Garmin g3 charts, which now (finally) include the integration of Navionics cartography data. The Navionics company, founded in Italy, introduced the world’s first marine electronic chart plotter in 1984 and has continued to develop cartography solutions for boating and fishing enthusiasts. Many boaters are familiar with Navionics, often hailed as the best marine charts available. This new Garmin g3 cartography includes much better detail that their previous g2 charts, including navigational aids, spot soundings, depth contours, tides and currents, and detailed harbors and marinas. For fishing, the new g3 charts offers seamless chart presentation with up to 1-foot fishing contours that provide a more accurate depiction of bottom structure for improved fishing charts and enhanced detail in swamps, canals, marinas and port plans. The top of the line g3 accessory card, Bluechart g3 Vision, includes everything available with BlueChart g3, plus high-resolution satellite imagery that provides boaters with a realistic view of their surroundings. The most desired feature of the g3 Vision is the shaded relief data, a high-resolution image of the bottom, with incredible lifelike detail of the bottom structure in water up to about 100 feet deep and good imagery of deeper water in the canyons.
Other brand of marine electronics
For those with a Navico family chartplotter (Simrad, Lowrance and B&G) the newly introduced C-MAP Reveal chart contains ultra-high-resolution bathymetric imagery. These charts too offer attractive three-dimensional views of land elevation and bottom contours bring to life the world around your boat. This allows you to visualize underwater pinnacles and topographical landmarks easier than ever.
CMOR is a newer mapping company, with products compatible with most Simrad, Lowrance and Raymarine chart plotters, as well as some Furuno multifunction displays. Back in 2017 a small startup company run by watermen, CMOR Mapping, released its first electronic highly detailed ocean-bottom and structure chart (Bathymetry) for Florida and have finally introduced a chart for coverage for our area in the mid-Atlantic. The CMOR map data is put together from multiple sources including commercial-grade multi-beam sonar and aerial LIDAR. CMOR Mapping has produced high-resolution Bathymetry at major fishing and diving regions. All vector data such as tides and navigational aids can also be viewed as an overlay. Pixel resolution is as great as 1 meter (each pixel represents 1 square meter of bottom). With depth shading on, every undulation becomes highlighted. Much of the amazing detail on the CMOR maps comes from aerial LIDAR.
Strikelines is also a newer company in the mapping business, specializing in detailed bottom contour charts, compatible with Navico and Raymarine products and also will run on smartphones and tablets.
These new charting options are a great way to gather more information about the fishing grounds and are another tool to help you catch more fish and enjoy your time on the water.
Stay grounded - Steve
