Yes you can! Get a good ground and measure the cable. I have done extensive fishing from Ak to Oregon with downriggers and had a black box for years. Used it for a while but it diddent seem to help. If your boat is running about .8 volts at the top then your pretty good for Salmon species. Coho like it a bit hotter but I never really targeted them. Kings like it abit colder...about .5 volts. You lose a wee bit of current as you go down so it seemed to be perfect for 10 feet to over a hundred. After outfishing many people many times I got rid of it cause I never turned it on. Aluminum boats are more prone to high currents. But measure your output before you spend the money. I would put my non black boxed boat against any black box equiped boat anytime. Also you dont have to buy a box to overcome the current. Its alot to do with installed components. circuts and placement of fishfinders ect. A fishfinder mounted closley to a electric down rigger can create a feild and be picked up by the cable. Aslo keep the electrics on there own circut and ground. Sometimes its a bad ground that can cause funky currents so check every fishing season and even chart the readings from year to year and what was done. You can learn alot about your trolling machine that way.

Bob D