At what depth are striped bass and bluefish? (saltwater new york)?

I want to try striped bass and bluefish fishing from my boat once the season starts up again. I have a few questions 1. What depth are these fish at? in some videos on youtube I see them jigging on the bottom with buck tails and other times I see them fishing on the top or middle of the water with spoons and buck tails, so how would you know where they are? 2. How do you target them? if they are on the bottom how do you only catch stripers and bluefish without catching porgies, fluke, and sea bass?
Please only answer if you are an experienced fisherman.
Thanks.

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