The tuna fishing off Key West, Florida, was super-slow on our last day of fishing. Not even a single tuna reported on the VHF radio. I’ve probably fished out of Key West 20 days across 25 years, so I’m no local expert. But I was willing to use any tools at my disposal to find some fish.
Toward sunset, someone told their buddy over the VHF that they, “got two tuna in 275 feet at the same spot as yesterday.” I bumped my radar screen to the 6-mile range, knowing that with the clarity of the VHF transmission, the boat had to be within 6 miles of me. So it was no surprise that I spotted a boat in 275 feet of water about four miles away.
We picked up and ran that direction. The goal was not to steal a fishing spot, but instead to look for fishy signs of life — something we hadn’t seen all day. As we approached the general area and deployed our spread, our son was fighting a blackfin tuna almost immediately as the sun set. Sometimes, the majority of fish truly are in a limited amount of water. Was what I did “cheating?” I’d say that with limited days to fish, it makes sense to take full advantage of every tool we have on the boat to catch more fish. Still, I would not recommend crowding someone’s fishing spot.
Familiarize Yourself with Radar
Radar is the best tool most boaters utilize to avoid collisions. Some boaters won’t turn their radar on until its dark or limited visibility. To me, that is pure insanity. If you want to be proficient when you need your radar for safety, and find yourself in a compromised situation, practice with it beforehand. You need to be comfortable using your radar regularly on the boat. Get to know your radar via repetition when on the water.
As you become more familiar with your radar, you will find you can quickly glance at the screen and greatly improve your fishing. My Key West example is one where combining VHF chatter, radar and chart plotter allowed us to find a bite before we ran out of daylight.
Read More: How Fishing Charts Have Revolutionized Sportfishing
Solid State Versus Magnetron Radar
The latest major technology advancement in marine radar is the switch from magnetron-based radars to solid state. While that’s a challenging topic to explain quickly, the result is easy to see and great for fishermen running to the offshore canyons in the middle of the night.
With a traditional radar, a 1/8-mile range was the lowest range you could view. In that range, there is a donut in the middle that no matter how much tuning you do, you simply can’t see anything in that region. Basically, the magnetron’s transmit power blocks any signal from coming back to the radar.
In a solid-state radar, the blind spots are gone, so you can see lobster pot buoys or other floating objects within a 200-foot range. That enables a safer early morning run to the tuna grounds.
Bird Mode on Radar
Finding birds like gannets, petrels, and frigate birds while offshore can pinpoint where fish are actively feeding. Results will vary, but you’ll want the largest open-array radar you can fit on your boat to have the best results when finding birds. Most modern, open-array radars offer a “bird mode” that will help you to tune in and see birds in the 1- to 6-mile range. This takes practice, but is very achievable.
Another example: What is that other boat doing over there? Finding new grouper spots is always a challenge when fishing a new area. I often fish new waters in my travels. While bottom charts continue to improve, seeing someone stopped off in the distance as you head to your spot is an opportunity to learn.
As I run the boat, I’m watching the radar overlay on the chart plotter and dropping a waypoint with a question mark symbol to designate a waypoint worth exploring. See a boat or group of boats? It might be a spot worth exploring later. To be clear, a boat stopped on a spot could just mean that the captain needed to refill his coffee. Or it could be a hard bottom spot that has great fish-holding structure. Once again, I do not recommend running up next to a boat and fishing next to it.
Radar’s MARPA Setting
MARPA stands for mini-automatic radar plotting aid. You mark a radar target and the radar will calculate and display range, bearing, speed and course. Each radar manufacturer has slightly varying functionality, but all modern radars can do this. When trolling the canyons, I mark as many boats as I can in order to see the speed of each of the boats within a couple miles of me. If you know canyon fishing, a ton of boats often fish within pretty close proximity at times. Many folks are trolling, but some are also popping and jigging.
When I notice one boat stopped that was trolling at a constant 6 knots, I drop a mark. If I see that same boat stop several times in the same area, that’s a pretty decent clue the boat found a group of tuna and is regularly hooking up. If I’m not getting bit, I might pick up and head that direction to see if the tuna have moved off in that direction. First and foremost, radar is for safety of navigation. Beyond that, experimenting and becoming a proficient radar operator allows you see the water around you. Use it like eyes in the sky. Knowing where other boats are keeps you safe, but it can also offer hints to better help you find fish.
About the Author: Louis Chemi’s lifelong passion for fishing is deeply rooted in his extensive experience in the marine industry. From his early days fishing in Long Island Sound to his time as a captain and mate on various boats, Chemi has accumulated a vast amount of on-the-water knowledge. With a strong foundation in engineering and marine physics, Chemi has also applied his technical expertise to the fishing industry. He has worked in various roles at Raymarine, Simrad, Lowrance and B&G, including developing fish-finding services and designing marine electronics. More recently, he spent time growing Freedom Boat Club’s franchise business. Today, Chemi continues to explore new fishing waters and share his expertise as a board member of the Recreational Boating & Fishing Foundation.
