Bassin' USA - Bass Fishing Forum Archives

Does anyone know what the circumference of a sonar cone is, rather how to determine it or how to approximate it. I was told by an exNavy sonarman that it's very complicated process. Any feedback out there? Carl

Carl,
Any sonar reading is determined by the water depth, in shallow water the coverage may be only a couple of feet, in water over twenty feet the coverage may be as much as fifteen. That's one reason that catching fish that showing on sonar can be difficult, it may appear they are directly beneath you but could be ten or more feet off to the side. Just remember, the deeper the hole the wider the angle.
I usually do not use a depth finder for any purpose than to tell me the depth, bottom content and if there is any sign of life below. If I'm not seeing bait fish or fish swimming in and out of the cone range I will usually move until I find these combinations. I have, on the other hand, caught bass when the sonar was showing nothing but the bottom, but I make long-parallel casts most of the time, so thoise fish haven't come into range yet. I have had success with side viewing transducers too, but don't get too excited when you see fish, since there's no distance indicator it may takle a lot of guess work anfd casting to catch one. Good luck and you've picked a great web site for information. Johnnie

Thanks for the feedback Johnie. This is one hell of a great site, best I've ever found. There are so many fishermen in this area, and so many tournys that guys tend to be tight lipped about the sport. I think you guys are very generious in sharing your experiences with us less experienced anglers.

Thanks Carl, we were all in your position when we started. Unfortunately we didn't have any web sites to help us and yes, some pros can be very tight lipped, won't find that here. Stay tuned for more. Johnnie

Carl,
Here is a close figure with which to work on determining the cone coverage at the bottom.

Many cones are 16 or 20 degrees. With that you can divide the depth by 3, and it will give you approximately the coverage area at the bottom. For example, if you are in 21 feet of water the bottom of the cone would be 7 feet. Just remember as the cone comes up it get narrower. In other words at 9 feet it would be 3 feet, and 3 feet would be 1 foot.

Best of fishing,
Dan

Thanks Dan, Carl