We know how passionate our customers are about fishing, which is why we've put a lot of time and energy into providing a massive selection of different fish finders from the top brands such as Humminbird, Raymarine, Lowrance, Furuno, Garmin and more. From portable fish-finders and ice-ducers, to GPS-Chartplotter/Fish-finder combo units, to black-box sounders to add to your current electronics network, we address all types of sounders, sonar and fish-finders on the market. Use our Refine Search feature to easily narrow your shopping results to find the perfect screen size you're looking for. Or check out the pre-matched product accessories such as transducers, mounts, and component cables for one-stop shopping.
Fishfinders (Sonar) - The Basics
How it works/key information - Greatly simplified, a sonar unit is just a combination of a speaker, microphone and stopwatch. Every fish finder "knows" that the speed of sound through water is about 4,800 feet per second. It transmits a sound pulse and then measures the time it takes for echoes to return from the pulse. Then it converts the elapsed time for each echo into distance. A built-in computer organizes all of this information and shows it on a display screen.
Pixels. Why are they so important? - The word "pixel" is short for "picture element". Pixels are the elements that the picture on a fish finder's screen is made from. Liquid crystal displays are really checkerboard-like grids of tiny dots (pixels) that darken individually when electricity is applied to them. A fish finder's computer forms the picture on its screen by darkening selected pixels and leaving others "blank". The number of pixels on a unit's screen determines how much detail it can show. Remember that pixels are arranged in columns and rows. The more pixels a screen has in each vertical column, the less depth each pixel represents and therefore the higher the resolution. The number of pixels in each horizontal row determines how long information stay on the screen before it scrolls off. This is especially important for units to show side-by-side displays of different kinds of information. Wide-screens allow information to stay on the display a normal length of time even when the screen is split into separate features.
Fish arches on your screen - The importance of seeing fish as perfect boomerang-shaped arches on the screen has been greatly exaggerated over the years. It all has to do with how fish arches are created. Imagine sitting in an anchored boat with your fish finder turned on. Picture in your mind the transducer's cone-shaped scanning area under your boat. In order to print a perfect arch, a fish will have to enter the edge of the cone, swim directly across the middle, and pass out of the cone. Let's say the fish holds a constant depth of 15 feet as he swims straight across the cone. The unit measures the distance to an object and starts to print out on the display; it's 15 feet below the surface of the water but probably 16 feet from the transducer. As the fish swims through the center of the cone, it passes 15 feet below the transducer. When it reaches the edge of the cone again, it's 16 feet away just before it stops printing on the screen. This causes an arch to start at 16 feet, curve up to 15 feet, then curve back down to 16 feet. The wider the cone angle, the more exaggerated the arch. If the fish changes depth, passes through only one edge of the cone, or wonders around under the boat before swimming off, it won't print as a perfect arch.
Power. Why is it important? - Power's importance is based on the perception that more power always produces a better echo. In reality, it is the combination of the unit's power and receiver sophistication that determines the unit's ability to find a fish and display an accurate image.
Which is better, wide or narrow cone angle? - Bigger is not necessarily better. A transducer with a wide cone angle scans more water as your boat moves along and can fish and structure features faster, but this advantage can also work against you. The wide cone may cover two or three important stumps on the bottom, for instance, and the lump their reading together, makes it impossible to see just the one with fish next to it. A narrow cone zeroes in on fish and can detect small details on structure features that fish may relate to. Focusing the transducer's power into a narrow beam also concentrates the sound output, enabling it to reach greater depths. A disadvantage to a narrow cone angel is that it scans smaller amount of water as the boat moves along. Probably the best of both worlds is using a transducer with a medium cone angle and automatically manipulating receiver sensitivity and echo filtering to provide wider coverage in shallow water and narrower, more detailed coverage in deeper water. Add the advantage of multiple transducer beams that look to the side as well as straight down, each with its own separate display, and it's easy to tell where fish are in relation to your boat.
How do I interpret what I am seeing on my fish finder display? - Some anglers don't stop and fish areas unless they see fish on the screen; this limits their success. Areas loaded with weeds, brush and submerge trees are great spots even if no fish are obvious. Developing the skill to see fish-attracting cover is as important as being able to identify individual fish on the screen.Any object that is different in density from water can return a sonar echo. It's the density difference that determines the strength of an object's echo. Clumps of weeds and branches of submerged trees poking into the cone angle have different densities, and return different echoes. It's often been said that 90% of the fish are in 10% of the water. Vast areas of any body of water are barren of fish, and fishing them is a waste of time. One great benefit of fish finders is their ability to help you bypass water that contains no cover, no baitfish and no lumps on the bottom that could be game fish. Ironically, one of their great benefits is showing you where NOT to fish.