Throwing the marker for offshore cover

[BassQualifier]

I have been attempting to become a better angler away from the shoreline and start locating and finding fish in the deeper waters on ledges, points and brushpiles that many other fisherman overlook. I idle the boat and find many brushpiles and other good looking structure on my sonar, however I am having a hard time finding it after I throw my marker and come back and fish.

I have been waiting to see the first sign of the structure on my sonar then I will throw the marker out probably 50 feet off the side of the boat so I don't sink the weight into the cover I will be fishing. When I turn around and come back to the marker and line myself up to where I remember the structure was seen with my sonar, I fish it with jigs, carolina rigs, etc and feel nothing. Sometimes I have tried casting 50+ times with no luck.

Is this just a skill I will have to practice at to find the cover I mark, or am I doing something wrong in the whole marking process? Thanks for your replies.