Depending on the species of fish, sometimes trolling the bait well above will trigger strikes. If you put the diver down ten feet for example, and the bait has a lip that takes it down 8 feet, than it will be at 18 feet. Just don't think you have to place it right in front of their noses every time.
As for planer boards, I've never ran jet divers off of them. I would run deeper baits off jet divers and then shallow runners off of the planer boards.
I hope that helps.