Currents keep going. Different depths can produce different currents.
For example. You are fishing 2.5 gps or SOG. 75 foot down the current could be moving at your boat from behind, sideways or in front of you. This all effects the speed of the lure you are using which can kill a fishes interest. Say the current is behind you, coming at your stern, you can go 2.5 SOG but the current is also moving at 2 mph. Therefore your lure has little to no action. Vise versa, if the current was at 2 mph from the direction of travel your lure may be spinning at the speed causing your lure to be moving at 4.5 mph which may be too fast.
You will be surprised the speed difference and even the tempo difference five feet at the lure can make .
Nick
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