TOPIC:

When trolling and marking fish at 20 to 30 feet does that mean they are suspended at that depth or were they at 10 to 15 feet down and dropped to 20 to 30 ft. when the boat approached?

When a fish is spooked by the boat, it's likely they go sideways more than down. In other words, chances are you won't mark them at all, especially at 20 to 30 feet where your sonar cone is quite small, even with a wide angle. My guess is fish marking at 20 to 30 feet are fish not bothered by the boat.

As BN pointed out at 20-30 ft your sonar cone is very small and if fish are marked they are pretty much right under the back of your boat if your transducer is mounted and angled properly. If you have fish moving up or down(streakers) they are probably reacting to bait if they are spooked by the boat they will most likely head to the side and out of the cone and not marked. Generally if you are seeing streakers in the upward direction they are actively feeding, in the downward direction they are not. If I see a lot of downward streakers I change up my presentation, especially flashers, as there is something they are not liking in my spread.

....Generally if you are seeing streakers in the upward direction they are actively feeding, in the downward direction they are not. If I see a lot of downward streakers I change up my presentation, especially flashers, as there is something they are not liking in my spread.

Very good info, thank you.