People leaning over the side to watch the release are prime candidates for this dope slap. When you get ready to head in, pick up the chum dispenser and dump the unused chum overboard. If a lot of chum is remaining put the chum in a bucket and refreeze it. If you use a chum bag inside a protective cage, drag the empty chum bags on a secure line behind the boat on the way home, a form of power washing-otherwise you'll never get them that clean at the dock. Something a shark fishermen has to be concerned with.
Galvanic action caused by dissimilar metals in the water gives off an electrical current.
Sharks are extremely sensitive to even the slightest voltage. Sharks certainly like the electrical field given off by a stainless steel shaft, a bronze propeller and rudder, and a zinc anode. You have brought the sharks to the boat by chumming, and sharks will hang around the propellers and rudders of boats,because of the electrical field. When you are leaving the shark grounds make sure that your props are clear of sharks. I'm not kidding.