Another Fishfinder Question - Sonar?

[minuteman62-64]

Probably a dumb question to most of you guys - but, in looking at fishfinder specs I notice that some (not all) specify "sonar" or maybe "sonar only" as one of the features. I thought a fishfinder was basically a depth sounder with added benefits. What's the difference between a fishfinder that includes "sonar" as a feature and one that doesn't?

 

[bruceb58]

Re: Another Fishfinder Question - Sonar?

A fishfinder is a sonar. Basically, a definition of an active sonar is a device that emits a sound pulse and listens for the return sound over a measured time to determine the range of the return. Same theory as radar but with sound instead radio frequency.

 

[Pez Vela]

Re: Another Fishfinder Question - Sonar?

So called fishfinders may be combination units which provide a sonar unit with a GPS chart plotter function. If the fishfinder unit does not combine both functions, it may be referred to as "sonar only" so that it is clear to the purchaser what he is, and is not, getting. A unit without sonar will never be referred to as a fishfinder.