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Ok, we've got a transom mounted transducer, I'm driving the boat and the Lowrance is just starting to show a stump, drop, brushtop, etc. Where is the dang thing? Under me, just in front of me or just behind me? I mean, it's like cone signal - isn't it? Or is it like hand grenades - close counts!!!!!??????
Just behind you!! :D
LMFAO to good.Well if it is transom mount I guess it is behind them :DQuote:
Originally Posted by BarryG
Seriously I have never own 1,but from what I gather its whats under you (I THINK) :confused:
I would have to say just behind you, as you see it appearing on the screen you have just past over it. Just like the TM, standing on the front you are standing on top of it as you past. Yes it's a cone but depending on how deep the water is depends on the width of the cone.
Thanks. If you think education is expensive, think about how much ignorance costs!!!!!!!!!!!!!!!!!!!
Not necessarily behind you. It depends on how deep the water is at that moment. If you were in a 10 foot boat with a 20 degree transom mount xducer and you were in 30 foot of water , it could be in front of you.:)
It also could depend on how fast the boat is moving, and how fast the chart scroll speed is set to.....I think..
It could even be in another lake, in another state. :)
(especially if you never turned the simulator off like me)
Buzz
Play with it. See it on your screen, drop a bupy. Turn around come back across it, see it on your screen, drop a buoy. Turn around cross it at right angle, see it drop a buoy. Keep doing this and you should have it surrounded by buoy. just like baseball. Practice practice practice.
Lowrance has a great tutorial on their site: http://www.lowrance.com/en/Support/T...onar-Tutorial/
A simple explanation is to imagine that your transducer is a flashlight. Close to the transducer, the beam is small. Further from the transducer, the beam is wide. In deep water, the beam is much wider, and may extend in front of the boat. Here's a good image from Lowrance's tutorial http://www2.lowrance.com/images/Tuto...r/colrmako.gif
This shows two things: First the beam spreading with depth. The second thing is that as the fish gets further from the center of the beam, the distance from the fish to the transducer increases, while the strength of the signal it reflects decreases due to the characteristics of the transducer. That's why the fish shows up as an arch. When the fish is at the edge of the beam, the return is weak and further away. As the fish goes toward the center of the beam, the signal shows as closer and stronger, then the signal weakens and shows further away as the fish moves back out of the beam.
Remember it is a cone angle and can also be right or left side of the boat!
Rowdy
:):):):):)Quote:
Originally Posted by Buzz
From why I understand, that when you see something come on to the right side of the screen, it is under you. But the time it gets a 1/4 inch on the screen, you are past it. Hope this helps.
Joking aside, this is a tough thing to learn and even a tougher thing to explain. Let's take a stump in my example that's 3' tall and 3' around. Let's say it was cut off by a chain saw. Let's say it's in 20' of water and you're using a 20 degree ducer. Somebody check my math on this, but the area of overage would be a circle roughly 40' in circumference. Further, let's say your ducer is on the TM.
OK, now, as you approach the stump as soon as it enters the ducer, which has coverage 20' ahead of the boat, it shows up, or at least start too. As you continue on, the signal gets stronger and the image climbs on the screen until you get right on top of it, when it is directly below the ducer. Again, as you continue on, the ducer continues to pick up the stump but with less strength untill you're 20' past it and the image decreases in height as you continue on. So, the stump doesn't show up as it actuall is like this:
___
| |
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It most likely shows up as varying degrees of signal strength and return, depending on how fast you're going and your scroll/chart speed like this.
^
/ \
/ \
OK, so how do you know if it's 20' to the left, right or center. Well, this requires trial and error and movement.
Let's assume you approach the stump running due north and pass the stump 10' off your port side to the west. As you approach the stump, the image climbs, when you're as close as you're going to get in my example, it begins to fall. As it begins to fall, let's say you guess it's to your right or East, so just as the top of the image begins to fall, you turn the TM to the right, but the image continues to fall. You then correct and steer back to the west and the image again begins to climb. Now as you pass over it, again the image peaks and you can confirm it's position by steering left and right looking for the peak of the image.
Now the hard part. You never really know what's down there nor the shape of the object, so a wad of brush will usually have a single highest point, usually somewhere near the center. A stake bed will have multiple tops over an area. A laydown log could have several high points. You really just have to move and make a mental image of what is there.
Lots of patience, practice pays off. Also, when you find something that looks interesting. Take a jig and work it and that'll help tell you what is down there and how it is oriented as well.
Or, you could just go get a 1197SI, find what you want, move your cursor over it and mark it. But that takes all the fun out of it. :)
Wannabe...
Not positively true. It depends on the cone angle, depth of water, system sonar settings, etc.Quote:
Originally Posted by rdant
Extreme right side (or A scope) is real time display. All display after that is history. A Scope is the flasher display kinda.
Lowrance has a good tutorial on this subject (as mentioned).
Below is a quick reference chart for the area covered by the specific cone angle listed. For example, if you are fishing in 10 feet of water and the cone angle on your transducer is 20 degrees, the area across the bottom is 3.5 feet.
* 20 degrees - 0.35 or roughly 1/3 of depth
* 24 degrees - 0.42 or roughly 2/5 of depth
* 30 degrees - 0.53 or roughly 1/2 of depth
* 40 degrees - 0.72 or roughly 3/4 of depth
* 50 degrees - 0.93 or roughly 9/10 of depth
* 60 degrees - 1.15 x depth
* 70 degrees - 1.4 x depth
* 73 degrees - 1.48 x depth
* 80 degrees - 1.68 x depth
* 90 degrees - 2 x depth
* 100 degrees - 2.38 x depth
* 110 degrees - 2.85 x depth
Find it on the graph. Throw marker in water in vicinity. Come back through in flasher mode and pinpoint. The flasher is money.
When I slow to no wake and im looking I get a marker ready if I see something I drop it over the side and it will pretty much be with in 4-10 ft behind it in 10-18' of water.
Thanks Cane Pole. I knew my rule of thumb didn't sound right.
Now if I can just rember......1/3, 1/3, 1/3, 1/3.
Nope, I've forgotten already. :)
Wannabe...
Buzz, I gotta go out and check my new deepmeter,and see if it is in sim mode. LOL.