Sonar pictures and big swell.

[johndeere]

Where I fish we often have a sea swell of 3-4 metres. A lot of the images for side and down imaging as well as the you tube videos seem to be taken on lakes or flat conditions. How well do these features show up when the boat is moving up and down a large distance? Are there sounders that can moderate this influence?
Also, normal sonar uses a beam. Within that beam the terrain could vary many metres in depth and yet at that instant you only get one depth reading on the screen. Does the unit average all the information within the beam?

[Noelm]

3-4m swell will show up as 3-4m peaks or gutters on the bottom, the unit does not know if the boat is going up and down, or the bottom depth is changing.

[battler1]

You can sort this out by adding a Sat Compass to your display if it acepts it My FCV1150 does it allows the sounder to have heave pitch & roll so no matter how big the sea's are you get a true reading of the bottom, i have a SC50 from OOPPS Furuno This compass also allows you get get true heading & Gps so if you have a pilot you can use it for heading & its accuracy to .5 of a degree and it has 3 GPS in her its the best you can buy & if you have a Sonar which i do you dont need a heading sensor.

Cheers Joe

Helpful twice tonight