I am often asked how and why I locate fish using my electronics and what the screen looks like when I see fish while running 20 to 25 mph. In the lake I fish Stripers are very spooky. If you go less than 5mph Stripers will get out of the way of the boat but if you can run at speeds where they can not escape you will locate schools of fish and bait much easier. When I am searching I cover as much different terrain as possible, checking out different depths, breaks, channels, creek mouths, humps, points etc. Once I find a particular pattern I use it to stay on Stripers through out the lake. Here are a few screen shots from my Simrad and I will try to explain what I am looking for. I usually use this same page setup while looking for Stripers. I like my Navionics map on the left, my echo or sonar page large enough to see fish and also I want my side scan working for me. You can click on the picture to enlarge it.
This is a great example of locating schools of Stripers while running around 25mph. Looking at my sonar screen what you see on the right side of the screen is what is currently under the boat and as you look back to the left you are looking into history. When I snapped this shot I had come off of plane and was only traveling 1.2 mph but on the left of the screen I was moving about 25mph. On the left you can see motor noise [small vertical dashes] then a tight group tiny red arches. This is what a tight school of Stripers look like at 25mph. I see them and start to throttle back seeing some scattered fish and as I slow even more to about 10 mph I clearly see larger arches [about midway on the screen]. I pull the throttle all the way back to stop and you can see as I came off plane from the surface down to about 20 feet air bubbles developed from my boat wash [rays of yellow]. Notice the slower I go the more defined and larger the arches are. When I am running I want to see motor noise which is yellow but I am looking for color, red on this particular pallet, which indicates something dense, either bait or fish. I also am looking at my side scan when I locating fish. On the structure part of the page [lower third in blue] the boat is at the top of the structure page at the number 0 and history is below it. I am looking 100 to the left of the boat and 100 feet to the right of the boat. If your transducers are set up properly you can use structure scan at ANY speeds, as can be seen in all of my screen shots. Now looking at the side scan I noticed while running 25mph fish off tho the left of my boat and as I slow down I continued to see more to the left vrs the right side of the boat. When I turned the motor off I deployed my trolling motor, turned it to the left where I saw most of the fish, put downlines out at 25 feet and before we could get many out everything hooked up.
In this pic again I was searching for fish running mid 20's checking out 30 foot flats nearby the channel. I went over the channel on the left side of the sonar page and saw Stripers [small inverted red V's] stratified 25 to 30 feet. I turned and came up on the flat and saw a few but hit the channel again and saw Stripers stacked in it. Again I had motor noise on the screen but I was looking for color which turned out to be Stripers. Unfortunately this is not a good fishing scenario, on this lake when the fish are in the channels they usually are not feeding. We can catch them on the edge or up on the flat but seldom over the channel.
This shot is just an example of when I run I have my sensitivity or gain up high enough to see motor noise but I am looking for color to indicate fish. Largemouth were positioned around 28 feet deep on the edges of this break and a few were suspended at the same depth off the ledge.
Sometimes Stripers are schooled so tightly they are hard to distinguish between bait or fish. Here I was running in the 20's seeing motor noise then tripped over a super tight ball of something. As I looked closer I saw arches in it so I turned around and checked it out. Turned out to be a very tight school of Stripers. We set up on them but only caught a couple. Unfortunately the Stripers that morning all over that area were tightly balled and it was frustrating to locate and catch just a few out of each school.
This particular day fish were relating to ledges, so I kept zig zagging over the drops trying to locate enough to set up on while running on plane. I finally located enough to set up on as you can see on the extreme right of the drop.
Hope this helps you decipher what you are seeing while looking for fish on your body of water. I will be posting more screen shots in the near future with explanations of what I am looking at on the screen. In the mean time come see us at the Sportsmans show this weekend, I will be in the electronics section of the Greentop's booth. We will be happy to answer any questions you may have about your units or to assist you in hooking you up with a great Lowrance or Simrad.