Help with identifying this.

[twofinbluna]

The way it goes all the way down through bottom all the way down the screen makes me think its some kind of interference, not anything actually below the boat.

[cold waters]

The way it goes all the way down through bottom all the way down the screen makes me think its some kind of interference, not anything actually below the boat.

my sentiments exactly

[rirockhound]

Yup.

Interference

[chumtini]

I took another look. It's not line/chain, unless it goes thru the seafloor

And seen by multiple boats. Strange.

[Avenger]

Connecticut River. Not far from Groton U.S. Navy Submarine Base and Electric Boat.

Hmmm................

[MikekCt]

I sent an e mail to Furuno and asked them what they thought of it.
Here is the reply I received today.

Response (Bill Allard) 07/08/2009 11:15 AM
Hello Michael,

Thank you for contacting Furuno USA, Inc.

The angular returns you see in these photos are the reflected bottom returns from another sounder nearby. Your sounder was receiving the sound pulse created by their sounder, and, apparently, they were also receiving the sound pulse created by yours.

This is an interesting image, in that this type of "interference" typically appears much lighter and more broken up, but this must have been one that had a pulse repetition rate just slightly off from your own and it had to be a boat that was close by.

Thanks again for contacting Furuno USA, Inc. We hope we have been able to answer your question. Please feel free to contact us with further questions in the future.