Anglers have always been able to view what’s above the surface of the lake, river or reservoir they are fishing. That all changed with the invention of “The Little Green Box” by Lowrance in 1957. The first sonar unit was all transistorized and over a million units were made until 1984. The Little Green Box revolutionized fishing and now Lowrance StructureScan is taking it even farther. Lowrance StructureScan consists of two powerful sonar views in conjunction with a built-in broadband sounder.

So, what is a Thermocline?  Webster's describes it as:
ther•mo•cline  noun /ˈTHərmōˌklīn/ "A steep temperature gradient in a body of water such as a lake, marked by a layer above and below which the water is at different temperatures."
Thermoclines can be observed in lakes and in the ocean as well. It's a phenomenon called stratification. During the summer, warm water, which is less dense, will sit on top of colder, denser deeper water, with a thermocline separating them. The warm layer is called the epilimnion and the cold layer is called the hypolimnion. Because the warm water is exposed to the sun during the day, a stable system exists, and very little mixing of warm water and cold water occurs, particularly in calm weather.

The biggest question I get at tournaments and fishing seminars is, "What do trees, rocks, grass, drop offs and fish look like on Side Imaging?  or I’m not seeing the same great stuff that other anglers are seeing.”  Understanding what structure and fish look like before you get out on the water can really help you learn how to find those areas quickly and eliminate a lot of frustration. Let's take a look at picture #1 which came from my good friend Doug Vahrenberg. This is a really great screen shot as it shows most of the different types of structure in one picture. One thing to remember about seeing structure on SI and DI is the size of the object.   That great looking tree shown so vividly is probably 40' tall! So, imagine how small a Christmas tree is going to show up. You also need to know that most of the real "Money" shots you see were a result of countless passes by the structure.  For example: If you're looking for a brush pile on a ledge along always go across the area at every angle.  Sometimes just the different contrast will show you the structure. Mark the structure with a waypoint and then go back over it with Down Imaging to really pick it apart. Another option is to bring the range in on Side Imaging to 35'-40' and get right beside it.

 

Unit  Name

Power Draw in Amps Lights Off

Power Draw in Amps Lights On

What is the Current Draw of my Humminbird Sonar Unit?

Sonar Units draw so little it’s hard to deplete a battery during several fishing days even with 2 of the bigger Humminbird 1198 units going. Below is a chart that illustrates the power draw by unit with and without the light function on. The chart covers almost every current Humminbird unit and a number of Legacy units.

 

I don’t think that I will be the only excited angler to find out that one of the leading authorities on fishing electronics will be writing articles and answering questions about sonar and GPS units on BradWiegmann.com. He has over 12 years of experience working with sonar and GPS units for Humminbird Electronics. So with any further ado…Heeeeeerrrrrrrreee’s Eddie!