Thread: Fish symbols or arches?

never knew what the difference was i thought they meant the same thing. i guess i should start reading the directions. But with a FF thats costs <$100 i mostly use it for depth anyway. thanks for the info.

Originally Posted by Crappisaurusrex

never knew what the difference was i thought they meant the same thing. i guess i should start reading the directions. But with a FF thats costs <$100 i mostly use it for depth anyway. thanks for the info.

thats my thoery, Tap you sure know your electronics, ive read my manual to my eagle FF but doesnt elaborate much. I really dont know much about reading them so i didnt put much money into it. Id definately consider upgrading if i could learn more about reading them.

I look for arches. If You set the graph up right with the right sensitivity and can read arches, they will eliminate a lot of water. This really comes in handy in the winter. You can find productive water pretty quick that way.CF

Whenever I get a new finder I turn off those stupid fish symbols. Anything that returns a signal will show as a fish. Whether it be a water logged leaf or an old beer can.

I keep my symbols off, although I rarely mark anything. Structure is ALL I ever see unless I'm in 20+ FOW, then and only then will I see a fish arch. I had never seen so many fish arches until the time I went with Tap to Buggs Island. That doesnt happen in SUffolk, atleast not with my depth finder.

And when I set up my Lowrance with the transducer on the trolling motor I remember there was a setting for how deep the transducer was in the water so it would compensate and read the actual depth of the water and the depth of the arches, not how far from the transducer the objects or the bottom was.

I have the fish symbols turned on, mainly cause I am blind as a bat while wearing sunglasses. The polarizing sunglases do reduce the visibility greatly and with the symbols on I can read the depth easier. The arches are all still there, so it is just an addition to what you are seeing. The computer determines weather or not to put a symbol on the screen based on the arch signal. So if it is a arch you are looking at you are making the determination. whats the differance? You still need to believe in your machine.

At BM when I go over a tree that is 5feet under the water I may get an arch and a fish symbol. I know it is a tree because the SI shows it. But it may also have a fish hovering over it. On most drops I see 3 or more arches. I know fish hang on a channel edge and the fish finder proves it. I saw many fish hanging at 23feet, could not hook one to save my life, but when I dropped a worm down to 23' bam! hooked up channel catfish. So now I know what is at 23'., cats.

Originally Posted by Flatwater

The computer determines weather or not to put a symbol on the screen based on the arch signal. So if it is a arch you are looking at you are making the determination. whats the differance?

My experience has been that you will see fish symbols where there are no fish. Does your unit put a fish symbol on a partial arch? If so, it will give you incorrect depth.

Here's a great link with lots of info. And here's a quote from it.

Advanced Fish Symbol I.D. is designed to give a simplified, easy to interpret display of suspended targets that are assumed to be fish. After gaining experience with your sonar, you will probably turn it off much of the time so you can see all of the detailed information on fish movement, thermoclines, schools of baitfish, weed beds, bottom structure, etc.

Here's a school of baitfish but if I had been using symbols I would never of known it.