BoatingOnly.com

Radar Navigation
By Capt. David Bacon
Reprinted from Sport Fishing Magazine, courtesy of World Publications

...In the old days, radar merely helped boaters avoid collisions. Modern radar technology provides us with tools to catch more fish. Skilled and creative skippers elevate finding fish to an art form. The art may entail staying an exact distance from a land-based target to fish the edge of a no-take zone or perhaps determining the course of a well-respected charter boat to learn where that skipper might be headed for the day. Let's see how much more ingenious we can become using radar.

...Heaven help us if we ever forget about the important safety uses of these devices. Radar helps avoid things that go bump in much the same way we use visual bearings. Any target approaching on a constant relative bearing represents a collision risk. Thanks to technology, we no longer need to make grease-pencil marks to track target positions and plots on the face of our radar screen as in the old days. Modern software and LCD displays perform that function automatically by creating lines called vectors.

...Opportunities abound for using radar to acquire fishing spots. After keeping boaters safe, finding fishing spots may be our next favorite use of radar. Many coastal areas have commercial lobster seasons, during which lobster boats place and service numerous traps around shallow and middepth structure spots. The livelihood of these lobster fishermen depends on their knowledge of subsea structure. Units that overlay radar and chart-plotter displays allow a captain to look for lobster boats or pots and to target those locations for fishing investigation.

...An option called Automatic Radar Plotting Aid (ARPA) tracks the course of multiple user-selected targets and displays a line (vector) representing each target's relative direction of movement. This helps avoid collisions, but also allows you to estimate another boat's course toward a fishing destination. When the target boat is one that regularly returns to dock with great catches, that information is worth gold. Follow that boat!

...Often, radar units allow you to place a cursor on a target and get a lat/lon position readout. You could stay over the horizon from the fleet's top skipper, but still see his boat on your radar. Place your cursor on his "blip" and save the position - you've just found one of his hot spots that you can take advantage of later. Other good boats to track to help find honey holes include crab trappers, bottom trawlers (watch for areas they maneuver around to avoid entangling nets on structure), dive boats and those of professional fishing skippers. The investment of a single day on the water just acquiring information in this way may well produce enough good fishing spots to set an angler up for the season.

...Along the way, radar may detect a squall while still at a safe distance. According to Larry Till at Furuno, the most useful radar for tracking storms - True Color radar - makes the denser parts of the storm readily apparent. Knowing where and where not to plot your route will help you make safer decisions when navigating through or around nasty weather. The marine electronics industry defines True Color as a display that bases the color of the target on the strength of the echo received.

...Practice makes perfect. To enhance your learning curve, sit in your boat in a slip or on the trailer as a strong weather front approaches and experiment with fine-tuning until you see the weather front clearly on the screen. Be aware, however, that in today's high-quality units, thanks to some very good engineering and testing, the auto settings may well produce the best signal returns under most conditions, negating the need to manually adjust radar.

...Nonetheless, it's definitely worth learning the finer points of your equipment. To get the most from a radar unit, some fine-tuning skills and understanding remain important. Experiment with your unit's gain - a common term referring to the receiver's general sensitivity control (much like volume). Sensitivity time control (STC) essentially reduces gain for nearby targets only, eliminating unwanted returns from waves. Some companies call this adjustment Sea Clutter. Fast time constant (FTC) controls the receiver's ability to discriminate against rain clutter. Note that some units, like Raymarine's Pathfinder, have both a rain control for close-in rain and snow and FTC for distant weather. These functions give a captain a better view of what's out there.

...Radar can prove invaluable for safely navigating through a busy channel, harbor, bay, or anchorage where visibility remains poor. Since charts can show only stationary objects, professional skippers such as charter- and headboat operators routinely run both chart plotter and radar to help spot any potential hazards to navigation. Seasoned skippers know that old charts often misrepresent the placement of buoys, docks, shallow water and other worries. Radar helps spot some of these anomalies.

...Most of us also keep a paper chart nearby. National Ocean and Atmospheric Administration charts are often old and lack details. Enhanced navigational-quality paper charts are available at most boating supply stores and fishing tackle shops. Never leave the dock without a good paper chart aboard because electronics can fail, leaving a captain with only the paper chart and whatever skills have been learned to get back to dock safely. This can be a scary exercise in dense fog or bad weather on a busy waterway. I highly recommend signing up for a public boating safety course with the U.S. Power Squadron or the Coast Guard Auxiliary. The USPS courses I took early in my boating career gave me a solid foundation of knowledge and skills.

...Selecting marine electronics involves decisions about whether to buy units that process and overlay displays from various inputs such as electronic charts and radar. On one hand, when anything bad happens to one multifunction display, the boat becomes severely handicapped unless redundant systems are aboard. On the other hand, the overlays make it easier to see differences between the charted and actual location of objects, as well as to observe the true or relative direction of movement of another boat and determine its destination on the chart. That destination may be the fabled fishing ground where the action is wide open.

...A parting scenario illustrates the ripe possibilities: You've spent the morning reading fish reports of great catches, but don't have specific locations. You subscribe to a sea-surface-temperature chart service, and today's picture shows a warm-core eddy with several pronounced temperature breaks. One of those breaks probably holds loads of fish, but they're too spread out to cover all in one day. After rigging some natural baits and heading offshore, you use your radar unit to track the course of two top charter boats. They run offshore in one direction, and then both turn to a new course toward one of the known temperature breaks.

...The cagey skippers were probably talking on cell phones and trying to keep their destination a secret by employing complex navigation tactics. You smile, knowing that you played your game just right and can look forward to an awesome day of fishing.

...About the Author: Capt. David Bacon is a veteran skipper, angler and outdoor writer based out of Santa Barbara, California. His customized 31’ Grady White, Wavewalker, can be chartered by parties of up to six passengers for exciting fishing excursions around the beautiful and productive Channel Islands. For more information, visit www.wavewalker.com, or call (805) 964-2046.

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