All of a sudden the bottom contour line is a wild sharp zig zag line instead of a smooth bottom.  What's up?  Tranducer?  Head unit?  Cable issue?

Waves?  If your boat is moving up and down the graph will show a zig zag pattern on the bottom.

 

Waves is my answer too.

No, not waves.  Waves are easy to see.  I'm talking about sharp vertical zig zags that are up and down 10 feet on the graph and very close zig zags...a 1/16 of an inch apart.

Going to need a screenshot or two to help diagnose then. All kinds of things one could imagine being the reason, but nothing better than us being able to see exactly what you're seeing in order to render judgement.

Waves over a drop off (aka modern day ledge)?

FM

3 hours ago, Bartableman7 said:

No, not waves.  Waves are easy to see.  I'm talking about sharp vertical zig zags that are up and down 10 feet on the graph and very close zig zags...a 1/16 of an inch apart.

Yeah, that doesn't sound like waves.  Sounds like your settings may be off.  T9 is right, a screen cap will help.