This page shows examples of bottom structure and fish as they appear on fish finders.
Identifying Fish and Bait
This image shows schools of anchovies below and rockfish in the 10-25 foot range in the Tangier Sound area
of the Chesapeake Bay. In this case, the location of the fish was indicated by gulls overhead.
These were large rockfish gathered under the lights along the pilings of the Chesapeake Bay Bridge Tunnel.
This image shows schools of small rockfish feeding on bay anchovies.
This image shows rockfish schooled along a ledge.
This image from an older Furuno unit shows a large school of menhaden in the lower Chesapeake.
Here is another huge school of menhaden in the lower bay.
These are also menhaden.
This image shows rockfish at various levels. On the right is bait which has been attacked and the school broken apart. Birds
were above as anchovies were being chased to the surface by the rockfish.
This image shows rockfish feeding in the water column on bait which has been attacked and scattered. Birds were above in this
This image shows a huge school of trout in the Chesapeake Bay. They were tight on the bottom in deep water. The fish readily bit metal jigs fished on the bottom.
Finding Shipwrecks, Reefs, Rocks, and Structure
This page shows fish finder screenshots of shipwrecks, reefs and other bottom structure. An explanation under each image will describe the target.
photo courtesy of NOAA
Before we start looking at images from fishfinder units, let’s look a data from a side scan SONAR. Notice in the image that the wreck has a scoured area of bottom surrounding it. Most wrecks don’t have quite this dramatic of a bottom change but normally there will be some scouring which will be a clue that you are close to the wreck.
This is a screen image of a large wreck off Ocean City, MD. Special thanks go to Capt. Monty Hawkins of the headboat Morningstar for this image. This is from a commercial quality color machine.
This image shows a wreck. Fish can be seen in the center of the screen.
The high section of the wreck appears on the right.
Notice in the left section of the screen that the bottom appears very thick. This is the low section of the wreck.
The low section may not have any apparent difference in height from the surrounding bottom but the thickness will give away its location.
The red above the wreck is baitfish.
This image shows another wreck.
Notice the abundant number of marks.
This is a mix of bait, fish and parts of wreckage.
This image shows a big mix of bluefish and rockfish in the Chesapeake Bay.
Notice the abundant number of crescent shapes (fish) along the channel edge.
These are piles of rocks in an artificial Reef.
The fish surrounding the structure were rockfish in the 22-26″ range.