However, fish finders for professional use, i.e., those used by commercial fishermen, can make use of other frequencies. Such frequencies include 15, 22, 28, 38, 45, 50, 68, 75, 88, 107, 150 and 200 kHz. There are some special fish finders that utilize the frequency of 400 kHz, but it is quite a rare case. As you can see, there is an extensive range of configurable frequencies available for fish finders for fishery vessels, and a fish finder generally makes use of a combination of two frequencies (high and low frequencies). The selection of the frequencies depends upon the intended purposes of the fish finder, which include, inter alia, finding specific fish species; grasping the seabed condition; conducting a wide-area-search with the search angle of 90 degrees at one go; conducting detailed search for fish schools; detecting fish schools that give weak echo returns; avoiding interference/conflict with other fish finders used nearby. The searchable range (depth) and search area are dependent upon the frequency used. On the one hand, high frequency ultrasound is suitable for a detailed search, although it cannot be used for search in deep water. Low frequency ultrasound, on the other hand, is suited for general searches in a wider area as well as searching in deep water.
As with many products, you’ll have to pay close attention to the specific features delivered for the price, simply because the investment for combination fishfinder and GPS can range from $500 to $1200 or more. Fishfinders and GPS units are well advanced when compared to equipment used just a few years ago. Most of the time you can get excellent 3D mapping, scanning, charting and navigation at a very reasonable price. It’s not necessary to spend hundreds more unless you really want to go after the top-of-the-line unit.
While not every object will be as easy to distinguish, you can always get clues from the shape and also the strength of the sonar return. Notice the multiple orange sonar returns underneath the car – these tell you that this is a very hard object. The sonar scans have hit the car, bounced up to the surface of the water, bounced off the surface and hit the car again.
It’s often been said that the act of fishing isn’t actually about catching a fish. Rather, it’s about a quiet moment with nature and a chance to sit, think and relax, whether on your bass fishing boat or on the banks of a river. Of course, if you’re a sport fisherman reeling in that prize monster on a white-capped ocean, there isn’t much relaxation to be had. If you prefer ice fishing or fly fishing, shop eBay for everything you need for a day on the water. We have the right gear for you, regardless of whether your allegiance lies with Orvis, Shimano or Abu Garcia.