Thread: Fish finder question

This has probably been covered before, but I couldn't find the answer in my searches. I went to the lake with my "new" boat for the first time today. Everything worked well, but one thing has me seriously baffled. I have a Lowrance Mark5 Pro fishfinder with the transducer mounted at the bottom of the transom. My problem is that I see what the screen is showing, but where is it actually???

For example, say I pick up a cloud of baitfish on the sonar with some larger fish underneath them. When that is showing on my screen are they directly beneath the transponder (ie. the back of the boat, so that means that once I see something I've effectively already passed it), or does the transponder read forward and detect things before I actually pass over them? I'm trying to determine whether I should cast directly beneath the boat, behind the boat, or in front of the boat if I see good fish on the screen??? Any and all input/answers will be GREATLY appreciated!!!!

(Ya know, you would think the manual would explain something like that so dummies like me don't have to ask silly questions!! Doh

What you see on the very right side of the screen is under the transducer. As it scrolls across it is going to the back of the boat. How far back depends on your speed. I use to have a depth finder that told you how far back things were but I can't remember what model it was.

Here's some info that may help you understand the shape of your sonar beam that eminates from the transducer....

Your exact sonar beam cone degree may not be the actual one depicted as I'm not sure what your cone angle is ......but the depiction gives a good view of what your transducer actually "sees"....

As Bill said....what shows on the very right side of your FF screen is directly in the sonar cone beam....what is to the left on the FF screen (as the screen scrolls) has already passed by the transducer and is behind your direction of travel....

It's a little more complicated than that but that's the general explanation.....

Remember....your not going to see anything on your screen that's not in that sonar cone angle beam....



Rickie

Thanks guys! That's exactly what I wanted to know. So when that school of baitfish first appears on the screen, it is approximately at the back of the boat and I will want to cast to the rear in order to intercept the identified targets/fish. That works for me!!! Thanks again guys. That's one thing I love about this forum -- someone is always able to give an answer to almost any fishing questions (and members do it without getting ugly with each other, which is increasingly rare on the 'net these days!).

Remember also that the xducer "Looks" straight down out of the bottom of the xducer....the angle that your xducer is sitting in the water will determine exactly which way the sonar beam is pointing....

You can actually adjust your xducer to point a little forward (maybe 5 degrees) and get the xducer to "see" a little more forward than straight down if that is something that may benefit you....

I have a 2d xducer on my TM that points forward 5 degrees....it actually shows stuff on my screen before my xducer is directly above it.....meaning that brushpile I see on my screen is in front of me a little...and not directly under me.....

Rickie