My unit i believe is showing phantom fish symbols was going to take the symbols off and just run on arches but can't get it to show an arch at all except on down image any help will be appreciated

Start by doing a reset all parameters. It will only change any custom user-defined settings.

Second would be to check for an update.

Third would be to go into the sub-menus and change the settings for sensitivity.

Also, fwiw you really should run with arches, rather than fish ID. You'll get a MUCH better feel for the fish, the sensitivity and where things are in terms of water column. It's much easier to decipher that information than it is with Fish ID on.

The unit will show more arches than fish symbols.

It will only show symbols of larger fish since it is programmed to only show air bladders of a certain size and up.

If you are seeing a lot of fish symbols, then you are around a lot of good size fish.

BTW, do you know why a fish is displayed as an arch on 2D sonar?

The unit will show more arches than fish symbols.

It will only show symbols of larger fish since it is programmed to only show air bladders of a certain size and up.

If you are seeing a lot of fish symbols, then you are around a lot of good size fish.

BTW, do you know why a fish is displayed as an arch on 2D sonar?

Is it the way a fish passes thru the beam that makes the arch?

Yes, the arch is a result of time and distance.

As Wayne kinda eluded to earlier, pay attention to the size and color of the center of the arch (the air bladder) instead of the size of the arch. The bigger and redder the air bladder, the bigger the fish. Bigger arches do not necessarily mean bigger fish. I like to turn my switchfire to max mode, then turn the sensitivity down to get a good picture. This will show you all the fish and make it easier to look for bigger bladders.

As Wayne kinda eluded to earlier, pay attention to the size and color of the center of the arch (the air bladder) instead of the size of the arch. The bigger and redder the air bladder, the bigger the fish. Bigger arches do not necessarily mean bigger fish. I like to turn my switchfire to max mode, then turn the sensitivity down to get a good picture. This will show you all the fish and make it easier to look for bigger bladders.

what do you like to run your sensitivity at in max mode. I usually run in clear mode but i'll admit i run in di,si most of the time

switchfire only applies to 2d mode not di or si. And I also agree that you need to get rid of the fish symbols. Turn them off!

If you're seeing arches, that means that your unit has passed over the fish from head to tail (or vice versa).

Why do fish show as arches?

Why Fish Arch

The reason fish show as an arch is because of the relationship between the fish and the cone angle of the transducer as the boat passes over the fish. As the leading edge of the cone strikes the fish, a display pixel is turned on. As the boat passes over the fish, the distance to the fish decreases. This turns each pixel on at a shallower depth on the display. When the center of the cone is directly over the fish, the first half of the arch is formed. This is also the shortest distance to the fish. Since the fish is closer to the boat, the signal is stronger and the arch is thicker. As the boat moves away from the fish, the distance increases and the pixels appear at progressively deeper depths until the cone passes the fish.

http://www.lowrance..../#Why-Fish-Arch

The reason i run symbols is purely for my fishing partner who most of the time is my dad and he is very impatience if he's not catching fish and he can see them little fishes on the screen he will keep fishing he doesn't understand sounders but those symbols are a life saver.

I don't use Switchfire Max at all. I get all the information I need (including fish arches)

with Switchfire Clear and the default Sensitivity setting.

The thermocline is at about 30' in these screen shots.

There are only two fish in this school that meet the criteria for a fish symbol. The symbols are blue since they are in the 83 kHz cone and not in the 200 kHz cone of coverage. There are several bass also, I caught two of them (on the right side SI view close to the bottom). This image and the other two are with a bow mounted SI unit and a trolling motor mounted transducer.

There are only two fish in this school that meet the criteria for a fish symbol. The symbols are blue since they are in the 83 kHz cone and not in the 200 kHz cone of coverage. There are several bass also, I caught two of them (on the right side SI view close to the bottom). This image and the other two are with a bow mounted SI unit and a trolling motor mounted transducer.

do you run with your noise filter off or do you run all defaults

Noise filter OFF. Never needed to use it. I don't want that interfering with the unit's sensitivity.

Thanks for the help