I rented a video a number of years back where this guy in Canada hooked a camera up to his downrigger, the one attached to his boat. Anyway, he shows how kings and silvers reacted to different lures, baits, and scents. The plug cut herring soaked in bildgewater and oil actually got more hits than the straight bait. I have seen some fishing shows where these guys used a similar unit to help ice fish as well. Seems pretty interesting for the curious, but what use it it? Sure you can see the fish, but you still can't make them bite unless they're hungry. If I am wrong, let me know how you use it to improve your fishing. Now people will talk about the one that almost bit, but got away .