I've never put out my own structure but I fish the carp out of it. Generally speaking I've found that when the fish are deep they are suspended, and they can move up and down throughout the day by 20+ feet. However those fish normally aren't relating to structure so having a brushpile at say 50 feet when the the fish are holding at 30 over 50 isn't really going to pay off except a few hours per day, unless it's a really tall brushpile. If your going to fish structure that is holding fish, you're going to be in 30 ft or less most of the time. At least I am. I dunno though really, I never really look for brushpiles in 50-60 foot of water while crappie fishing, so I could be completely wrong. Maybe someone who has set out some really deep structure will come along. If nothing else you could always fish it for cats.
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