Individual dark vertical lines in bottom lock mode

[mrfisherman]

No picture but I noticed I occassionally see invidual dark vertical lines in the bottom lock mode starting about ~50-100 feet up going to the bottom. Color of the lines is dark like bottom. Is this just noise or are they really fish marks? Pic speed is 1/1.

Thanks.

 

[Snips]

mrfisherman,
Thanks for the post. But without seeing a screen shot or knowing what sounder you are using it is hard to offer any suggestions.

Snips

 

[mrfisherman]

Snips,
FCV295. No picture but I drew it up. Looks like this below. Any ideas if that is just noise or fish?

 

[Snips]

When spikes appear you really need to look at the right side (Main screen) for reference. Spikes can appear because the BL function is locking on the wrong part of the bottom return. Sometimes turbulence can cause this as can to much power. Try using a Short 1 or 2 Pulse Length to see if that helps.

Snips

 

[mrfisherman]

Snips,

Right side of the screen doesn't show anything visible other than the bottom since it is too deep anyway (500+ feet). So I take it you're saying that it is probably just noise and not fish marks.

Thanks.

 

[Snips]

mrfisherman,
Unless I am trying to determine bottom hardness I will always use the shortest pulse length that the sounder has. One the main reason is that the TX rate increases with shorter PL's. The faster the TX rate and the faster your screen advance is so you are getting more information from the sounder. Below is s screen shot in 600ft (100fm) showing what I mean and also you will see your bottom spikes. Even though there is an random spike they don't affect the fish detection.

Snips

 

[mrfisherman]

Snips,

Thanks for the suggestion and pic. Will give it a try!