Pro-Troll Black Box
Cannon electric downriggers have a feature called Positive Ion Control (PIC). The PIC is a rheostat on the downrigger that allows a fisherman to adjust the voltage level being emitted through the downrigger cable provided you’re using cable. The Cannon short stop system will not function if a superbraid line is used instead of the stainless steel cable. The high end Cannon downriggers with a PLC like the Digi-Trol, Marlin and Mag 20 models should be able to use the superbraid line.
Below is information Cannon provides about their Positive Ion Control function on their electric downriggers. As Greybeard said the voltage emitted in fresh water shouldn’t be an issue provided your boat and downriggers are grounded properly. As you’ll read if you are using Cannon electric downriggers the Lexan bodies insulate the Cannon downriggers from any possible hull stray voltage. Just another reason why Cannon downriggers are top of the line.
The Positive Ion Control System Your boat has an electrical charge around the hull in water. If a boat is properly bonded and properly zinced, that charge should be slightly positive when measured from ground to the downrigger cable. Positive Ion Control (PIC) is the use of electricity to control that charge and its fluctuation so that it is always maintained at a specified set voltage. The practice of setting up and maintaining a slight positive charge on fishing gear has been used by commercial fishermen for many years. This practice has enabled some fisherman to increase yield when used along with other good fishing and boating practices. Cannon's electric downriggers offer fishermen a big advantage in being able to stabilize and control the positive charge around their boat. Because of the Lexan® construction of the frame, Cannon downriggers are insulated from your boat's hull charge. When the stainless steel downrigger cable is lowered into the water, the natural ionization between the cable and the boat creates a positive charge of 0.7 to 0.9 volts in saltwater and 0.3 to 0.6 volts in fresh water. This natural voltage is dependent upon salinity and mineral content of the water. Your actual voltage may vary.
Always make sure the boat is properly grounded to the water. This will help ensure proper PIC voltage on the cable and that the Short Stop will function properly.
WIRE SPECIFICATIONS: 0-15 ft. (0-5 meters) 10 gauge 15-25 ft. (5-8 meters) 8 gauge 25-30 ft. (8-9 meters) 6 gauge
Any power boat can leak electricity into the water via the engine that's why there is the sacrificial zinc anode on the lower unit. If there is stray electrical current the zinc gets eaten away rather than the lower unit. Whether that charge can be picked up in the water by the rigger cables is beyond me.
Some do use superbraids on their riggers as it does reduce blowback. I tried 150# braid and shortly thereafter lost the whole setup. Not sure but likely a nick in the line. I abandoned and back to stainless. At least if a few strands start to go you might see it and salvage before a loss and that has happened a number of times over the yrs.
If I recall correctly to check for stray voltage you run a wire from your negative post to a voltage meter and that to your rigger cable that is in the water. Check out the Scotty site for more details.
I used to have one but parted with it as all my riggers checked out with OK voltage without it.