Full Circle

A favorite of tournament anglers, Omni Sonar provides a 360-degree picture around the boat to help crews find more fish.

The first rule of fishing is pretty simple: You must find the fish before you can catch them. When fishing a small body of water, locating fish is somewhat easy. But when you’re fishing for marlin or tuna along the continental shelf in several thousand feet of water, the fish have a distinct advantage. At least they used to.

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Captains rely on an ever-expanding arsenal of electronics to help them in their quest to locate fish. Radar is used to spot birds diving on bait. Satellite imagery pinpoints temperature breaks and blue water. And fish finders paint a picture of what’s lurking below the boat. The latest and greatest device, ­however, is the Omni Sonar system from Furuno, which sends out a continuous signal 360 degrees around the boat so you can spot game fish and/or bait ahead, behind or off either side. While this technology has existed for a long time, it only started ­showing up on sportfishing boats about five years ago, and it’s getting more and more popular. Now, you can hardly compete on the tournament circuit without it.

“Omni Sonar has been around for more than 40 years,” says Matt Wood, national sales manager at Furuno. But because of its price tag and the size of the equipment, this sonar ­mostly lived on commercial fishing vessels. That changed when a few of the top offshore skippers on the tournament scene saw what ­sonar could do and pushed Furuno to offer a package that would work on large sportfishing yachts. “These were guys who were already very competitive tournament fishermen and wanted to take it to the next level,” Wood says.

Furuno offers a few different models of Omni Sonar, but the CSH8LMK2, or “8L,” is the most popular on ­sportfishers. The 85 kHz unit blasts out a mid-frequency, 360-degree ­transmission about five times every second. This lets the captain, or in many cases a crewmember whose job it is to watch the sonar all day, see what’s going on around the boat in real time. The functionality lets you tilt and train the center of the beam to zero in on bait and individual fish. The information can be displayed on any MFD or monitor, and it resembles the circular image you see when using marine radar.

The Omni Sonar continually transmits a signal around the boat to pinpoint baitfish and/or game fish up to 5,000 feet away in any direction.

The Omni Sonar continually transmits a signal around the boat to pinpoint baitfish and/or game fish up to 5,000 feet away in any direction.

“On screen, you have an icon of where the center of the beam is, how far away it is and where it is relative to the bow of the boat,” Wood says. “We can shift that beam up and down based on where animals are and use target lock to keep the center of the beam on the target.” The sonar will supply the lat/lon of the target as well as a bearing to intersect the fish. It can even engage the autopilot.

Furuno says the 8L has a range of 5,000 feet, but a lot of factors come into play that affect how far it can pick up returns, the foremost being salinity levels and water clarity. The sweet spot is more like 1,000 to 1,500 feet, or even closer. “Captains will use Omni to get close to the fish and hook up. Then they retract the sonar because you don’t want the fish to wrap the line or wire leader around the transducer,” Wood says. That transducer is an expensive piece of equipment, and when deployed, it extends a foot to a foot and a half below the keel of the boat.

The basic hardware, including a transceiver, transmitter, hoist unit and control keyboard, retails for around $80,000 and jumps to about $100,000 to $150,000 when installed. Mounting these systems is quite a bit more involved than a typical transducer. The hoist unit that holds the transducer is a long tube that needs about the same standing room as a man inside the boat. And since the best picture comes from a sonar placed directly on the keel, you may need to get creative to retrofit a boat. Sometimes the tube will start out in the engine room and extend into an unused cabinet in the galley or a bulkhead. With a new build, the tube can be incorporated into the layout and you won’t have to jump over as many hurdles. The more room the boat has, the better off you’ll be, but crews keep squeezing them into smaller boats.

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“When we started doing these installations, we said 60 feet is about as small as we want to go,” says Wood, “but our customers take us places we would not go ourselves. That has happened here.”

Furuno has installed Omni Sonar in large center consoles and even a lobster-style Down East boat that was just 19 feet. To get the best picture you want the transducer mounted on centerline in the keel about midship, so when deployed it shoots the signal out from below the keel line with no keel shading covering up any of the sweep.

While it may seem crazy to a casual angler to drop that kind of money, tournament teams see this as an investment. It’s an unparalleled game changer that you can’t compete without. It’s the new 40-knot speed barrier. These offshore crews are fishing big-money events with multi-million-dollar payouts, and the majority of the boats on the leader board use Omni Sonar. With that kind of prize money on the horizon, it’s no surprise that the top sportfishing boatbuilders are all becoming experts at installing this totally tubular technology.

This article originally appeared in the May 2021 issue of Power & Motoryacht magazine.

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