That would depend a lot on the sonar, and the ducer, as well as what you compare it with. :)

For mapping, the major issue with CHIRP is the varying conenagle.

OK so it possible that depth numbers will come out sometime irregular using chirp sounder ?

This is an interesting article from Biobase on using using CHIRP compared to 200 Khz fixed frequency, especially what bottom composition is concerned.

cibiobase.blogspot.be/2015/07/chirp-from...ing-perspective.html

thanks for the link..

I love my TM150M (Medium CHIRP) when looking for fish in the watercoloumn, but for pure mapping I much preferr my P66 (fixed 50/200).

Ok do you hock the p66 to a lowrance head unit ?

This is very good article about this subject..thanks

DiveExplorer wrote: Yes. I'm lucky enough to have three HDS-units and two sounder-modules in my boat so I can have several ducers plugged in at the same time. I just change "source" in the menus depending on what ducer I want to use.

If I where to have just one ducer, that would be CHIRP. Simply because my main interest is fishing. Ducers that are good for showing targets (fish) in the watercoloumn will never be ideal for mapping, simply because of the coneangle.

Thats awesome.. thats way it so good to hear from you guys that have the equiment... the toys ... and also have the experiance in those things.

My main intrest is mapping and searching.. so I dont think that Chirp is not mandatory in those things.

Chirp you can select frequencies as you need , fix lowrance for bottom composition, or higth for 3D, use too down to get better map of wreck with pencil tool.

OK so there can be some benefits using Chirp into mapping..

fisching and look at fisch chirp is top, DI can help too, for looking at wreck or any structure DI and side are best and for mapping a traditionnal transducer is enougth!