How to read my fishfinder?

[OhioLowell]

Hello all. I've been lurking around here for some time now and I have a dumb question. I have a Eagle Cuda 128 finder on my boat. MY question is: The screen is constantly scrolling (unless you turn off the scrolling feature) so how do you know what is directly under the finder? I'm not really sure where certain structure starts and stops while the boat is moving due to the scrolling screen. If anyone here could lend me a hand with this would be greatly appreciated.<br /><br />Best,<br />Lowell

 

[cp]

Re: How to read my fishfinder?

The bottom that appears at the right edge of your screen is what's most recently under your transducer. Everything to the left is history. Suspended objects (like fish) are not necessarily directly under your transducer, just within the cone of sound projected by your transducer.<br /><br />This is not a simple thing to master, given that the screen is a 2-dimensional representation of a 3-dimensional real world, and there is relative movement between the boat and any fish within the cone of the transducer. Suggest you read the sonar tutorial on the Eagle website Click here, then go use your fishfinder over known bottom structure.<br /><br />There's no substitute for experience. Good luck.

 

[Boatist]

Re: How to read my fishfinder?

I agree with pchonda.<br />Watch your unit when you first turn it on. You may get a logo or something but then the right most row of pixel will display the echos of the first ping the unit send out. Next the display is moved one pixel to the left and unit sends out another ping and again displays echos in the right most row of pixels top to bottom.

 

[Moody Blue]

Re: How to read my fishfinder?

I like to put mine in DEMO mode. Can see all sorts of perfect fish arches and very well defined bottom detail and structure. Can never seem to get anything close in the REAL world display <br /><br />Picture an inverted cone /\ below the transducer. The finder will display anything within this cone area. The deeper the object the wider the cone is, so in fact the object may be several feet away from the center of the cone which is theoretically directly below the transducer.<br />I try to adjust the scroll speed to approximatly match the boat speed.

 

[jtexas]

Re: How to read my fishfinder?

What you see on the screen is (or was) somewhere within a circle with its center at your transducer and with a diameter of approx 1/3 the depth (assuming a standard 20 degree cone angle). So if the 'ducer is on the transom, the structure you see on the bottom in thirty feet is somewhere within 5 feet of your stern and the fish suspended at 18 feet are within 3 feet. No clues as to actual position front-to-back or side-to-side.<br /><br />Technically, the radius of the circle equals depth times the tangent of half the cone angle, and the cone angle varies with the sensitivity setting, but the 1/3 rule of thumb works pretty well.

 

[bolo789]

Re: How to read my fishfinder?

man i have a furuno LS 6100 black and white, this year is my first boating season before i those a fishfinder i read a lot of thread on this forum ant the money i have to spend at the time was getting a goog low price unit man man great units, i snag a bunker and put a weight on it and send it down below the boat every time i send it down i saw it appear on my screen so after that i know if iam out and see those same reading i have an idea what size is fish or bait is down there i even put my long crab net down belo and sees it apear on the screen, great unit with taht test i was able to locate bait school and fish in may and put a lashing on them stripers, everything the guys state above is real, what just apear on the right of the screen is what under the boat at that moment, when it reach the middle screen going to the left is history good luck.

 

[OhioLowell]

Re: How to read my fishfinder?

Thanks for the info guys! I hope to be able to use my finder a little better now. I really love to fish but I must say I'm not very good at it. I would love to be one of those guys who can fill a stringer every time he goes out no matter what but I've still got a ways to go there. Thanks again.<br /><br />Lowell

 

[Silvertip]

Re: How to read my fishfinder?

To get a good idea of what you are seeing, try and run a body of water that has a sharp dropoff (like a river channel) and that you are very familiar with. Steer at 90 degrees to the side of the channel (go slow) and you will see the edge of the channel and a corresponding change in depth. Now turn right and follow the edge of the channel, steering away from it and then back again to get an idea of time delay and a as was pointed out, a 2D perspective of a 3D under water world. LCD locators take a second or two to process the sonar pings so what you see is a couple of seconds behind you.

 

[Bob Fort]

Re: How to read my fishfinder?

As you start to use your fish finder, know that the only useful info you will get at first is the depth at which the majority of the fish seem to be located. That's good enough to send the bait/lure on its way and get fishing.<br /><br />As you become familiar with your unit, you will develop some confidence regarding other info provided by the unit. For example, I use a Raytheon L365. By using both focused and broad beams, I can determine which hits are near the boat and which are on the outer fringe of the cone, etc.<br /><br />Good luck with finding and catching the fish you seek.