Bathy Charts

In many ways, marine fishing is a lot like hunting. It doesn’t matter whether you’re after billfish, tuna, dolphin or shark; the ground rules are the same. There’s a vast array of open water out there and only a small fraction of it is likely to have the prey you want.

Before you have a chance to catch your prey, however, you have to find it. And once you manage to pinpoint a "life zone," you need to optimize your plan of attack to present your baits or lures while the feed is still on.

Fortunately, today’s anglers have an arsenal of advanced electronics at their disposal to help level the playing field. Expert offshore anglers use state-of-the-art electronic charting systems with high-detail C-MAPNT vector-based electronic charts to find and catch more fish.

Here are some tips from the experts on fishing with C-MAP electronic charts. Perhaps you can adapt some of these to your style of marine fishing and put them to use the next time you head offshore.
 

 Fine-Tune Your Drift Patterns 

Captain John Raguso, professional New York-based charter skipper and magazine editor, has a reputation for getting his customers on big mako sharks. "I use my C-MAP electronic charts to see how my boat is drifting in real time and make subtle changes based on the effects of wind, tide and current," said Raguso. "I can relate my boat’s movement to the 20-30 Fathom Fingers on my charts and, if need be, reposition the boat, power drift or do whatever I have to, to put myself where I think the fish are."

Live Bait Means More Fish 
 Captain Ray Rosher, skipper of the Miami-based custom charter boat Miss Britt, specializes in live bait kite fishing for sailfish. He credits his consistent ability to find quality goggleye, pilchards and other bait as a key reason he has won sailfishing’s Triple Crown two years running. "The bait can be harder to catch than the sailfish, especially the goggleye," quipped Rosher. To tilt the odds in his favor, Rosher runs two powerful Simrad combo sounder/GPS/chart plotters on his boat: a 14" CE-40 in the cabin and a 10" CE-32 in the tower, both with C-MAPNT electronic charts. "Over time, I’ve saved about 20 spots on my electronic chart plotter where bait can show up, which gives me an automatic edge. By referencing my waypoints, the detailed electronic charts and what I’m seeing on my powerful color sounder, I can even tell if it’s the species of bait that I want."

Focus on Structure
"When I'm trolling Hudson Canyon for tuna, I'm always working structure like pots or drop-offs — never open water where there's nothing," said Raguso. "It's a three-sided canyon with lots of nooks and crannies, covering about 100 square miles of ocean. You could easily spend all day and not be in the game. Using my GPS and C-MAP electronic charts — especially the high-detail bathymetric charts — helps me focus on productive water and position the boat where the fish will be."

Track Your Success
Captain Rick Gaffney enjoys guiding anglers into bluewater action spots across the Pacific. But when he fishes in his home waters off the Kona coast of Hawaii, part of his recipe for success is Furuno's C-MAPNT-compatible GP-1850 DF combo sounder/GPS/chart plotter.

"Sometimes I like to fish along the 1,000-fathom line and the electronic charts let me know where I am, even if I'm well beyond the range of my sounder. You also see where you've been, so I mark where I've caught fish. By relating those marks to the bottom detail on the charts, I get a good feel for what structure the fish are relating to, allowing me to focus more in these areas," said Gaffney.

Hit the Thermoclines
Rosher loves to target broadbill swordfish at night and his Simrad electronic charting system with C-MAP charts plays a big role. "The powerful sounder on my CE-40 is able to pick up thermoclines (temperature breaks) deep in the water column," said Rosher. "By marking these on my C-MAP charts, I'm able to fish in the right place at the right depth for these elusive fish." Since strong thermoclines often present a wall that helps corral baitfish, this same technique of finding them with a powerful depth sounder and targeting them with C-MAP electronic charts can be used effectively for many offshore pelagic gamefish.

Be a Better Weed Whacker
During the summer and fall months, Rosher can often be found in the tower of his sportfsher, looking for weedlines that hold dolphin. "Being able to see the bottom topography on my chart plotter is vital, because there's a definite correlation between the structure on the bottom and weeds on the surface," explains Rosher. "When you're fishing the Gulf Stream or any place with a lot of current, bottom contour helps create flows and eddies that form weedlines. Based on the direction and speed of the current, I'm able to use my GPS and C-MAP charts to spend less time searching and more time catching. And having a second chart plotter up in the tower lets me look with both my electronics and my eyes."

Mark Life Zones
"Anytime I'm out on the water, I'm on the lookout for bait, birds and other signs of life," said Raguso. "Sometimes I'll be on my way to an area and I'll pass through something that looks fishy. Even if I don't get bit, or if I'm not going to fish the area right away, I"ll save it as an event on my plotter. Over the course of a day, you can start seeing some patterns and you might retry some of these spots later in the day when conditions are different."

Rick Gaffney concurs, stating that he uses his electronic charting system to keep a record of all indicators that could lead him to fish later. These include visible signs like bait, birds or feeding gamefish along with less noticeable factors such as strong current lines.

Coordinate with Friends
Working as a team with other captains is an excellent way to maximize fishing time — and marine chart plotters play a pivotal role. "I often stay in touch with friends and we alert each other when we find fish," said Rosher. "Whether I'm getting the information or giving it, my chart plotter and C-MAP electronic charts make sure it's not just a blind guess. If someone tells me that the dolphin are running 12 miles off the reef, I can just put the cursor at the right depth or distance from the drop-off, mark the spot and go. Likewise, if I want to share with other captains, I can just center the cursor on the position on the C-MAP chart where I'm catching fish. I can quickly relay the distance from the reef to other skippers."