Fish finder question?
 

I could use any advice that you guys could offer. On my fish finder, it has a setting for fish symbols, or for the fish to be displayed as arches. If I set it for fish symbols, I can't tell if I am marking bait or bigger fish. (I have it set for various sizes also) If I shut off the fish symbols, the fish alarm goes off and I see a gray blur. I am yet to see it display an arch like the manual says. The fish finder came with the boat and it is in grayscale. Am I just inexperienced, or should I just go buy a color fishfinder? Or is there something else I am doing wrong?:doh:

What is the brand and model of the fishfinder?

i'd upgrade it
 

i especially like the units with the sidefinder technology
although it's not offered by all manufacturers.
Garmin has it... i believe? and then you can mark fish near the surface
and cast right to them with a top water bait.\

the technology has advanced since your unit was built.

Try turning the sensitivy or gain down, I never run it more than half way. Shut off the fish alarm. My Humminbird shows bait as the small hollow fish stacked up like cord wood. On my Furuno without fish ID bait looks like a beard or fuzz growing off the rocks. It takes a long time to get used to figuring them out. I like the Humminbird easy to run.

I have the garmin blue 160, like I said it came with the boat, so it is obviously atleast 2 yrs old. I bought a garmin chartplotter before the season, so would like to stick with garmin. I guess if I could just learn how to tell what is bait size fish and what is a big fish, I would be content. Do you guys feel that the color ones display the size more accurate, or am I reading this one wrong? Like I said, just haven't seen that "arch shape" yet.

The faster the scroll speed of the bigger the arches, at least thats the way it worked on my old B&W. I just purchased a Furuno 620 and I also have the Gamin chartplotter. The differance between the color and the black and white is, well you can't just describe it with words. Below is a picture of fish from the East poart of the bay this week.

I have an older RayMarine...but have owned/operated Hummingbird and Eagle. I normally shut off the fish symbols and manually adjust sensitivity so I get lots of noise, then back off just until noise disappears. If a fish swims under the boat - you'll see an arch. For me, bait usually shows up as a large black glob or ball. I really am not an 'expert', but I do trust that if there is NOTHING on my finder that there is probably not going to be anything biting my bait/lure!


One thing....I assume you are underway? If you are anchored and chunking....you won't see arches in most cases. Mostly dragged out lines (again, depends on chart speed setting). My unit also has a "flasher" feature which is nice for those times when I am not underway.

Anyways...do a google search for "fish finder arch" and you'll find lots of info such as

http://omp.gso.uri.edu/work1/people/fishing/1.htm

The importance of seeing fish as perfect boomerang-shaped arches on the screen has been greatly exaggerated over the years. It all has to do with how fish arches are created.


Imagine sitting in an anchored boat with your fish finder turned on. Picture in your mind the transducer's cone-shaped scanning area under your boat. In order to print a perfect arch, a fish will have to enter the edge of the cone, swim directly across the middle, and pass out of the cone.


Let's say the fish holds a constant depth of 15 feet as he swims straight across the cone. The unit measures the distance to an object and starts to print out on the display; it's 15 feet below the surface of the water but probably 16 feet from the transducer. As the fish swims through the center of the cone, it passes 15 feet below the transducer. When it reaches the edge of the cone again, it's 16 feet away just before it stops printing on the screen. This causes an arch to start at 16 feet, curve up to 15 feet, then curve back down to 16 feet. The wider the cone angle, the more exaggerated the arch.


If the fish changes depth, passes through only one edge of the cone, or wonders around under the boat before swimming off, it won't print as a perfect arch.

great post Jim H !
 

in addition some people like to have dual fish finders
one on the back and one in the front so they can tell which
way the fish was swimming by listening to both..

lowrance claims you can have enough sensitivity
set...so that you can see your lure movement...

also you can troll swimmers til you get a strike then circle
back and watch your fishfinder unit.... findem.

Thank You.
 

I went and bought a color raymarine. I used it last night...........love it. Was able to mark the pogie school when I went over them, and was also marking various size fish. (not w/ fish symbols) Unfortunately, I didn't catch a thing. One quick hit on a live pogie, but he only ran for 2 seconds, I couldn't even try to set the hook.