Topic: fish id

[sblatt]

im having some trouble seeing the difference between fish and other objects in water. my question is does any use the fish id on there humminbird units. what does a fish look like with fish id off? thanks for the input.

[edwardpic]

I think some of that depends on the water clarity and fresh or saltwater. I do have the fish ID on, but most of the time rely on SI, DI or 2d sonar to get a good look at whats beneath and around me. For me fish show up as arcs or on a rock pile per say an object suspended just off the bottom. With SI, depending on your settings, you can see the actual fish, I fish saltwater and a lot of ledges or rockpiles so the SI really shows me whats around. Long winded response, but, learning the unit and making settings changes should really make the fish stand out. Everyone uses different settings so find what works best for you. Happy fishing!!

[ITGEEK]

For 2D, I always have the fish ID on.
The nice thing about the HB units, is that even with fish ID on, it will still show the arch below the fish symbol.

Without the fish ID on, the fish will look like arches or boomerangs.

[Doc Stressor]

Humminbird appears to use a really good algorithm for their fish ID. It's much more conservative than what Lowrance uses to draw artificial arches all over the screen. I've found that most of the symbols are really fish. The only thing that fools it are vertical ledges with high relief.  Irregular projections along the ledge or sometimes weed growth will usually show up as fish symbols. But for suspended fish, it is usually dead on.

Remember that only fish that use their swim bladders to remain neutrally buoyant will show up on a fish finder. Fish that are chasing bait up and down in the water column will not show up.

[Double Digit]

I was out this past Friday and ran into a HUGE striper and bluefish blitz.I always have my fish ID on but this is the first time i seen it work and this was the first time there was no doubt that i was over tons of fish...I was very impressed with the fish ID....Here are the pictures i took during the blitz....

[ITGEEK]

Doc Stressor,
I disagree with your swim bladder statement.

I think a fish always uses it's swim bladder.  It may expand or contract, but it's always there, and probably always has some air in it.  If it has air in it, then it will show up on the sonar.  However, the fish does have to pass through the sonar cone/beam to be seen on 2d sonar.

Think about bait that is scurrying to get away from predators.  They are not  using their swim bladders to remain neutral, but are hauling ass.  They show up on the sonar.

[Humminbird_Greg]

There is also a rule of thumb that states that approximately half of the sonar return is from a fish’s swim bladder while the other half is split between the scales, flesh and bones.  These also can reflect sonar and will show up but as a weaker returned signal.