Setting up your sonar

[Nightprowler]

I found this article interesting and thought it might help understand your sonar unit a little better. ENJOY!


Modern LCD or liquid crystal display Depth - Fish finders are computerized and offer a menu-style operating system. The angler presses a combination of buttons to navigate around the menu and can access different options until the desired setting is reached and imputed.

Most Depth - Fish finders also have manual and auto settings. By simply turning on your unit you will be using the pre-programmed automatic settings. These include pre-set gain, surface clutter, fish icon indicators and other signal processing settings. My first bit of advice here is to familiarize yourself with the options and the automatic setting pre-sets (Read the owners manual). Doing this will allow you turn off the auto option and further customize your depth finder when you will most need it.

Once you know how to turn off certain auto settings, turn off the fish i.d. or fish icon. Sure little fish of all sizes look good on your screen, but they are often not fish and can be confusing to a new user.

Chad Warford of Lowrance Electronics says while the auto feature is very handy for general use of a depth finder, most upper-level anglers will usually tailor their units to the situations they are seeing the most on the waters they fish.

When you are in manual mode it all comes down to resolution and target separation. Being able to distinguish targets that are six inches apart versus three inches apart allows anglers to see much more. In the auto mode you won't see as many fish and tend to miss much of the total picture.

You actually have get out of the auto mode and then select your upper and lower limits in order to get the better resolution. Just remember, the smaller the window; the better the resolution," notes the marketing director for the Oklahoma-based electronics giant.

Furthermore, Warford says in the manual mode, "ideally you might want a 30-foot window. At this point, separation can be as good as 1/4-inch apart with an X-75 or X-85."

Just about any medium to high resolution unit can offer this type of resolution, you just have to know how to set them up. Warford revealed a little math axiom to check your resolution/target separation no matter the unit.

In 50-feet of water with a 100 vertical pixel unit you divide 100 by 50 and come up with two or 1/2 for a half-foot resolution. In 60 feet of water with a 240 vertical pixel unit you divide 240 by 60 and get four or 1/4 and discover your targets are separated by a mere 1/4-inch.

Referring to Warford's comments that "the smaller the window; the better the resolution" -- remember when in auto mode, your depth range will be set and reset according to a computer program. Often if you are in 25 feet of water, your unit will choose to scan a range from 0-60 feet. This is not efficient as you are wasting a lot of your unit's power scanning right into the lake bottom. To overcome this problem, switch off of auto mode and set your own depth range - often eliminating the top few feet and stopping the scan about 10 feet below the actual bottom.

[chuckauten]

Thanks for the info.

[beagle man]

good stuff thanks

[DTG]

I got one for ya. When you offset your depth to give you depth from top of water, fish are shown on sonar, is their depth from top of water or from transducer on trolling motor? 2ft can make a diffrence in catchin fish or not.

[CrappiePappy]

I got one for ya. When you offset your depth to give you depth from top of water, fish are shown on sonar, is their depth from top of water or from transducer on trolling motor? 2ft can make a diffrence in catchin fish or not.

... and I believe the consensus was that depth of fish/structure was measured from bottom of transducer to the object, and not from water's surface. Which would make sense, since transducers are at varying depths, according to the boat they're on and whether or not they're on the transom or trolling motor (how deep your boat transom sets, and/or how deep you run the head of your trolling motor).

I don't know as it amounts to TWO foot of depth difference (never put my trolling motor down that deep :p ) ... but, your point is valid --- even a foot difference can make you drop your bait too shallow, under some circumstances. That's why I always "adjusted" the depth (in my mind), by adding 1ft to the depth listed on the screen (when measuring from surface, or using a float & /or tightlining)

... cp

[Don G]

I got one for ya. When you offset your depth to give you depth from top of water, fish are shown on sonar, is their depth from top of water or from transducer on trolling motor? 2ft can make a diffrence in catchin fish or not.

Depth Offset will adjust the digital depth readout to indicate depth from the
waterline or boat's keel. Enter a positive vertical measurement from the transducer
to the waterline to read the depth from the waterline. Enter a negative vertical
measurement from the transducer to keel to read the depth from the keel.

My transducer is on my trolling motor & is 1.5' below the water surface...Therefore I go to the "depth offset menu" and set it at +1.5'..This then measures your target from the water surface..

[jnash75976]

Thanks for the info.

[DTG]

So when offset the fish reading is the correct offset depth. fish @ 12' is at 12 ' not at 13'6"

[Cane Pole]

Chad Warford of Lowrance Electronics says while the auto feature is very handy for general use of a depth finder, most upper-level anglers will usually tailor their units to the situations they are seeing the most on the waters they fish.

I don't meet this criteria. So, it is automatic mode for me. Wonder what the fish will think of me now that I have been exposed?.

[Cane Pole]

My wife likes to see the fishes on the screen. Keeps her happy and that keeps us out on the water longer. She could care less about offset and arches and other bunk. I don't dare remove fish ID.:o