Fish finder interpretation

hoga10

Member
Joined
Jan 12, 2007
RO Number
24844
Messages
21
Hi all,
A fishing newbie here. I've been reading Capt. Tom Hughes post below and it's great that he enclosed pics of the fish finder. Unfortunately, I have no idea what's going on in those picts. I'm thinking of getting an Eagle 320 fish finder. Can someone lead me to a website that would tutor me on how to read or interpret grayscale fish finders. Thanks.
 
Try here....download a maual and read how to interpet the readings...and by all means keep one thing in mind.....Fish finders lie !!!

[http://www.eaglegps.com/Downloads/Manuals/default.asp]
 
I've had my fishfinder for 15 yrs, so my technology may be out of date. But I've found it will indicate there are fish when there are not. However, it is always correct when it says there are no fish! I've stopped setting the fish alarm.
 
By the time the fish finder finds them they're GONE..
 
There's two aspects to the fish finder. Some fish show very well on the screen and others don't. Any fish that has an air bladder will show. Large, suspended fish show well. Fast moving Salmon don't. In the case of Salmon, you learn to look for the bait. Anchovies show as giant haystacks under water. Sometimes you pick up a small dot to one side or the other. That would be the Salmon.

Now, in shallow water with a noisy boat, the fish wont stay directly under the boat. So you wont see them.

With lake trout, you would use the finder to spot the thermocline. (the separation between lower cold and upper warm waters) The fish will hang out right on the edge.

With delta stripers, you would use line counter reels. Using the depth sounder, you would troll the rivers, adjusting line in and out to keep the lures right on the bottom. The bottom isn't flat, so you spend your day adjusting lines, using the sounder to track the depth changes.

Keep in mind the primary use for the fish finder, is keeping your boat from running aground.
 
Sometimes I have been monitoring the FF while we are anchored and bait fishing. I'll tell my SO there is a school of fish at 12 ft. He'll adjust his line to twelve ft and get a hit! Trouble is, they not be keepers........
 
OK, I see what you guys fellas are saying. So fish finders are not really to find fish but used mainly to find structures or indicators where fish will be. I was thinking of getting a fishfinder to make fishing a little more interesting for my young son. At our lake we have small mouth bass, crappie, catfish, and trout. Thanks.
 
One thing to know about fishfinders is that the better ones have two choices of transducers. One will be extra wide, for shallow water fishing. The other is typically a dual beam transducer, the 200 khtz will be a narrow beam and the 50 khz will be wider. These are typically used in the ocean for fishing depths greater than 100'.
 
One thing to remember: NEVER use the "fish symbol" feature. If you do, every bubble and weed the unit picks up will show up on the screen as a fish icon. Turn the gain up til you start to get "clutter" on the screen, then back it off a little. When you start marking bait, look for "hooks" around the bait. That's what you're looking for. The dual freq transducer is a good thing. When I'm up running, I always use the 200Mhz setting, as it punches a signal down a little better. When I set down to fish, I switch to 50mHz to get a wider view, maybe see some fish that are moving out to the side from the boat. Remember that any fish you mark may not show the true depth on the graph: a fish marked at the side of the transducer cone is actually shallower than it appears on the screen, as the transducer measures the distance from the transducer to the fish. If the fish is to the side, it is measuring the side of a triangle. The diameter of the circle on bottom covered by a 50mHz transducer is roughly equal to the water depth, so in 100fow, a fish could be 50ft to one side of the boat. Play with the unit while you're out, It take a season or two to get really comfortable with a unit. I'm currently running a Raymarine L750, and I like it, but I'm going to upgrade to the DS600x digital color unit soon. It's really great. It will operate fine without making any adjustments. As Ron Popiel says: "just set it & forget it". My disclaimer: I'm strictly a freshwater boater and fish salmon in the great lakes. This will be my 41st year. Current boat is a 28ft Slickcraft HT with 2x351s.
 
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