Rookie Question about my Fish Finder

[MikeVJ]

Hey guys,

Here's a few pics from the end of last season in the Brewerton Channel (Patapsco).

I'm not really sure ('cause I'm new) what I'm looking at in these images. Therefore, I can't learn from them... In both cases, I didn't catch anything after looking at these types of echos for hours at a time.

Are the small marks Rockfish and the large marks are bait? Or is it the other way around?

Anyone have any tips...? I really want to get better at this.

Thanks,

Mike