Of all boat accessories that make fishing more enjoyable, sonar is arguably the best. It wasn’t always that way. My first unit was a Lowrance flasher, and I was excited to add it to my 1977 lime green sparkly MonArk equipped with a 90 hp Chrysler outboard. Even before I mounted the transducer, I was already counting all the millpond largemouths my flasher would find me from the Delaware ponds and rivers I fished.
As I recall, a bracket not unlike modern versions was simply screwed to the glass console, and the transducer was screwed to the transom and plugged into the back of the flasher with a ¼ inch phone jack. Power was the typical black ground and red positive that attached to the boat’s fuse block under the dash. That is where “simple” ended.
For those not familiar with flashers, a light that would flash every time a spot on the spinning disk reached the top position. This represented the depth of zero. The flasher would send out a sonar signal, and when the signal reflected back from the bottom, a second flash of light would appear at a different spot on the spinning disk, and a scale marked around the disk would represent the depth of the bottom. As a depth finder, these were a huge improvement over poking your rod into the water to find bottom, especially since most of the rods we used were only five foot long. It also beat casting a Carolina Rig and counting how long it took to reach bottom, as you couldn’t do this under power.
Flashers were touted to also show you underwater weeds, trees, and fish; all of which were revealed by a third flashing light between the zero light and the bottom light. This is where the trouble started, and the enjoyment began to get questionable. If you think modern electronics are complicated, you don’t understand the challenges of sonar interpretation in the early tournament years. WesternBass.com, YouTube, and even the internet didn’t exist to teach you about sonar, and how to interpret the display.
In truth, only those who really wanted a flasher to show them fish and structure, and practiced with them on the water were able to benefit from the technology. Most could not make the leap of faith to believe the flashes of light represented fish, let alone realize with practice they could distinguish trees, weeds, and fish. At best flashers were only depth finders to many.
Many to this day are unbelievers. Despite living in an electronic age rich with GPS, Broadband Sonar, StructureScan, and now SpotLightScan, those who embrace the technology and practice with it will enjoy their fishing more than the others. First it helps to believe these advanced High Definition screens are formulating a picture for a reason. Once you trust your HDS unit, you need to learn how to interpret it. Options include personal instruction from experienced users, internet forums, videos, and more.
DownScan technology has made believers of more anglers quicker than any other technology. Anyone who has ever looked underwater and viewed trees, rocks, and weeds on the bottom of a lake could recognize immediately the same images created on their DownScan screen. Both DownScan and SideScan technology draws nearly exact pictures of objects underwater from thin slices of sonar and advanced software that assemble highly detailed data into images.
SideScan is a little more difficult in that your view is out to the sides of the boat, so the picture does not relate directly to your traditional down view. But for those who take the time to learn how to use and view SideScan, for the first time you could search for and mark fish and objects far out to the sides of your boat, rather than immediately below it.
Which brings us to the latest trend in sonar imaging. SpotLightScan refers to a new technology from Lowrance that allows the angler to sweep a sonar signal 360 degrees around the boat with the use of a foot control (cable-operated) electric motor. Picture holding a flashlight in the dark, and sweeping the light around you to spot objects in the dark. SpotLightScan does essentially the same thing, but the light is replaced by sonar, and fish and other objects spotted with the scan are drawn on your screen. They appear very much like your SideScan and DownScan images.
If you have used StructureScan before, much is the same in that you still have DownScan, but your SideScan view is replaced with SpotLightScan. With this display, your boat position is in the center of the screen, and objects spotted are displayed on the screen in relation to your boat position. If fish or rocks are out to your left, they will show to the left of your boat on the screen.
Using the new 3.0 software upgrade for HDS Gen2 units (download for free from www.lowrance.com) your display includes a measurement scale. This allows you to see how far away the fish and objects are from your position.
Mounting the SpotLightScan is simple, and there are several videos on You Tube that are excellent. Instructions are also provided, and for those like me who actually read instructions, will find them useful. To use this technology you must have an HDS Gen2 unit (Touch or Push Buttons) and a NMEA 2000 network installed on your boat. Your electric motor must be a model that is steered with cables, because there is a position sensor that attaches under your pedal. As you raise or lower your pedal to rotate the scan beam, this sensor sends its signal to your HDS unit through the NMEA 2000 network so it can be properly oriented on your screen. Once installed, accuracy is ensured by a simple calibration process performed with your HDS software. If you have a Touch Screen unit, there are no additional parts to buy. If you have the non-Touch HDS Gen2 unit, you will also need to add a SonarHub which the SpotLightScan transducer plugs into.
One important setup key is the proper adjustment of your electric motor cable. Most electric motor foot pedals have a cable tension adjustment screw. This needs to be properly adjusted to allow smooth steering of the electric motor, with no slippage or slop in the movement.
There are no power or ground wires to connect with SpotLightScan. A single transducer pod is attached to your electric motor. This pod includes the SpotLightScan transducer, a DownScan Transducer, and a traditional 2D Broadband sonar transducer. A single cable allows for a clean install, and the cable splits at the end to attach to the StructureScan port and 2D Sonar port of a Touch Screen unit (or to a SonarHub for the non-Touch HDS Gen2 units).
Images from SpotLightScan can be displayed on multiple HDS Gen2 units as long as they are connected with Ethernet cables. Likewise, if you have StructureScan attached to a different HDS unit, it can also be displayed on your bow HDS unit connected to the SpotLightScan. The ability to share and display all transducers on all HDS Gen2 units is a great feature of which experienced users take advantage.
Learning to operate the SpotLightScan transducer is the biggest challenge, but in very short order you will progress from wondering if you will get it, to wondering how you did without it. The key is in understanding how the technology works; and more specifically how the transducer works.
The transducer sends out a thin slice of sonar in the shape of a fan. If you drew a 45 degree angle on a sheet of paper to represent a fan, then turned the piece of paper on its edge so the angle is pointing with the open end forward, and so the top angle line ends pointing at the water’s surface, and the bottom end of the other leg of the angle is pointing down to the bottom, you would have the concept of how the transducer points. When you rotate your electric motor, this fan rotates with the motor, sweeping the area in which the transducer points with the slice of sonar. As the signal reflects back from objects, the distance and shape of the object is depicted on the HDS screen relative to your boat position and distance.
If you are stuck in the 1970’s, and don’t trust sonar to tell you the truth, then SpotLightScan will not make your fishing more enjoyable or successful. On the other hand, if you are like me and want every advantage possible to find and catch more fish, then you will want to take advantage of this technology.
I now use it in conjunction with my Point-1 antenna when approaching a waypoint I want to fish. I use SpotLightScan to find the structure represented by my waypoint, and because I spot the rock pile without having to run over it first, I am able to cast directly to it, or to the fish if they are out to the side of the waypoint. I also use it to scan a flat or ledge for schools of bait or fish, or to spot new structure (I didn’t know existed) that might hold fish.
If you want to look under docks and spot fish or brush piles, and be able to know where and how far to cast, you will want SpotLightScan.
In my experience to date, I can’t say it always draws perfect pictures that clearly illustrate the target it finds. I doubt the technology is capable of this since the picture quality is affected by the speed of your sweep, the distance to the target, and the size and type of target. But it doesn’t take a leap of faith to realize it is showing you both fish and targets once you learn to trust the technology. The clarity of the picture of the bass doesn’t make it more or less worthy of your cast, what’s important is spotting the bass so you can cast to it and catch it!
SpotLightScan draws the image because the object is there; many times it is clearly a tree on its side, or a school of bait with large fish to the left or right, and sometimes it is simply something different than everything else around. Even these targets are worthy of a cast, and now you know where and how far to make your cast!
It took me years to learn how to interpret my flasher to tell me useful information beyond the bottom depth, and it never could show me where to cast to connect with a school of bass, or to a rockpile, unless they happened to be directly under me. Times have changed with technology; and for the better for those willing to embrace it! Ciao! Marc Marcantonio
Marc’s sponsors include: Lowrance, QuickDrops dropshot weights, Yakima Bait Co, Ranger, Evinrude, Pacific Boatland, Lucky Craft, Lamiglas, Gary Yamamoto Custom Baits, Gamakatsu, McCoy Fishing Line, Solar Bat, Stealth Charging, and TaySys Software.