It takes 250 ft of line out to make a Bandit 300 series dive to 19 feet (which is it's terminal depth). Anything over that distance and the bait will actually ride up in the water column. Conversely, it only takes 160 feet of line out to reach 18 feet down.

If you put your crank on the back of an Offshore tadpole, it only takes 25 feet of line to reach 18 feet. Just a thought.

The above numbers were taken directly out of the "Precision Trolling" app which is also dubbed "The troller's bible".