It all will depend on your speed and weight of the ball. As a general rule, a 45 degree angle on your cable will put your ball about 10' shallower than what your footage counter says at approx. 100ft. The current also will play a part as will the amount of drag of your outfit. I usually run 10 - 15 ft more line out on my cable than what the bottom reads. As stated above, expriment with your gear and you'll get a pretty good idea really quick. Just remember that the ball on the side you turn towards will sink deeper as you turn so be ready to bring it up if you bounce. Good luck and let us know how you do!