Mackeral & Cod shown on a sounder

[wildcard]

From time to time I hear that mackeral can't be seen on a sounder or fish finder to give it another name because they have no swim bladders. Here is a pic to dispel this myth which are from my own boat fishing off Saltburn last year. The mackeral are shown as red/blue bands. Sometimes the shoal is so dense that the sounder gives false bottom readings and the screen goes totally red (a red out). This shoal was over 8 miles long.

 

 

 

 

Here is one of cod feeding on the bottom taken on the same day.

 

 

 

 

wildcard

[gannet]

Depends on what frequency the sounder is operating on.

[wildcard]

Depends on what frequency the sounder is operating on.

 

The only two transducer frequencies I know are 50mhz and 200mhz.

 

Mackeral would only be feeding in relatively shallow depths of less than 600ft I would think so 200mhz is the only one I know for shallower water or do you know of others?.

 

I don't suppose you would see a red out on a monochrome display either

 

wildcard

[gannet]

I don't suppose you would see a red out on a monochrome display either

 

wildcard

Agreed there wildcard.

[Davy Holt]

Hiya,

 

I get mackerel showing up no problem on my Raymarine C80 when using the 200 htz transducer.

 

One question though is how do you know the shoal was 8 mile long ? it could just as easily have been a small shoal heading the same speed and direction as you

[big_cod]

Big marks on sounders are often feed not large shoals of bigger fish 10 years ago i was absolutly amaized one day when cod were jumping aboard if you were to 10 hooks on you would have pulled them up 10 at a time and the daft thing wasnt even a scratch on the sounder this seems to happen rarely but it does baffle you sometimes like i say the big marks on sounders are often feed with the bigger fish flying around feeding i have a koden cvs chromascope set on 10 fathom expansoin it is a very good set and the discrimination is excellent.

 

paul.

[wildcard]

Hiya,

 

 

One question though is how do you know the shoal was 8 mile long ? it could just as easily have been a small shoal heading the same speed and direction as you

 

Never thought of that

 

I read a post once where an angler was amazed at the amount of fish under the boat but couldn't catch anything. He then realised the sounder was in demo mode....

[Toerag]

'catchable' fish always show up as some sort of horizontal or diagonal line in my experience. big 'blobs' of fish are baitfish.

Sounder frequency - of use to UK anglers are 200 and 120kHz (I have a 120kHz Koden), with maybe 50 in really deep (400ft+) water. Commercial sets also have lower frequencies available, these offer better seabed discrimination so scallopers use them to find the best scallop gravel.

Edited January 26, 2009 by Toerag