Thread: Help interpreting this

So speeding up would make them arch better?

Yes and depending on unit, a faster chart speed will shorten the arches

The boat was trolling into the waves so the bottom and the fish are somewhat jagged in the first pic, but also longer due to the slow speed.
This was due to the boat surging and stalling.
The second pic was smooth trolling at a higher speed.
Both shots give you examples of various sonar returns.
The solid line in pic 2 is a downrigger ball and the thinner line just above it is the lure attached to the ball.
Notice the thinner line is somewhat jagged as that is the lures action as it moves around in the water.