Not sure what the hum?..never heard it before?
I started my adventures on Lake Michigan when I got my first boat in '72, a lowly 14' Sea Nymph that had no business being out on such a large body of water. One had to watch the weather closely and pick very calm, cloudless days to venture out. My first boat had Luhr Jenson down riggers that used 10 lb weights, and over the years I progressed to larger and larger boats. I upgraded 4 times over the years to my present 20' Lund. Each boat was larger in size than the one it replaced.
The down riggers I've used over the years have had weights that ranged in sized from 10 pounds, then 12, then 15 and 16 pound weights. The heavy weights allowed the weight to track under the boat and be visible on the sonar as a line running across the graph. As the boat moves through the water at trolling speeds for the lures being trolled, the speed of the boat was usually between 1.5 mph to sometimes over 3 mph. When the weight was attached to the 150# test steel cable, the down rigger wires will hum a high pitched whine. If you have ever used down riggers, I'm surprised you have never heard what I'm talking about. Very noticeable in every boat I've ever had.
Now let's assume you've launched at a popular fishing port like Ludington, where on the weekends, hundreds of boats launch there and spend the day with their lures attached to the release at the down rigger weight. All of these down riggers in the water and the associated hum/whine the down rigger wire makes slicing through the water at the speeds I mentioned will alert fish to the boats presence. Some fish will move away from this presentation as the hum of the down rigger wire alerts them. This is why fishing my lures 100 yards or more behind the boat works better than lines that have lures close to the boat.
Knowing what the hum of the down riggers wires can do to move fish away from the passing boat makes presentations with planer boards and Dipsy Divers very effective. It allows one to present the trailing lures off to the sides of the boat. When a boat with humming down rigger wires passes over a school of fish, they will part off to the sides of the boat and this puts them into position for the lures trailing off to the sides of the boat with Dipsy Divers and planer boards, and not underneath as would be the case with a down rigger presentation.
I've attached a pic of some I caught using the poor man's down rigger weights, where most boats were only getting one or two. Sometimes it's the little things that pay huge dividends. These poor man's downrigger weights were made as a mother of invention. The first ones we made only had on release on them, and after having the weight fall off the fishing line from a fish that hits was frustrating. Landing the fish on which the weight was attached with one Off Shore release eased the loss of the weight, Off Shore release, ball bearing swivel, and O rings, but it still was painful on the wallet.
Sometimes a King Salmon also called a Chinook can attack a lure at up to 30 mph and this speed would sometimes cause the weight to fall off the fishing line it was attached to with only one release holding it to the fishing line. That is when we modified them for two releases and it solved the problem. I've been trolling for trout and salmon on the big lake for 54 years and I'm quite good at it.
Another aside for using the poor man's downrigger weights as they work on other lakes for other species. Lake Erie for walleyes, and another large inland lake called Higgins Lake where there are some very nice sized trout and these one pound weights work there as well.
I could write another long post about using a casting net for getting some alewife's which are the preferred bait fish for salmon. Basically get good at using a casting net. Cast for some alwife's or bring some fresh store bought smelt which are another preferred bait for salmon and keep them on ice.
Any lure that gets set behind the boat first gets slimmed up with the bait fish that salmon eat day in and day out. This slimming up our lures before setting them up for trolling behind the boat gives off the aroma they are use to homing in on with their incredable sense of smell. Parts per billion. Scenting up lures with bait fish they eat everyday probably quadruppled our catches. We figured this out in the early 80's as I used to launch my 16' Sea Nymph at a small creek called Stoney Creek. My partner and I would have our waders on and had a 4' tall x 15' long net stretched between two conduits of half inch EMT, and we would run down stream in this small creek at the mouth of Lake Michigan in the wee hours of the morning when it was still dark and net a bunch of alewifes.
We would put them in a bucket and throw some ice on them. This allowed us to scent up our lures with the fish they eat the most. Alewives are an andromonous invasive bait fish that migrated in from the Atlantic ocean and are now found in all of the Great Lakes. This species of fish was so prolific that they lined the shoreline of the Lake for miles when a die off occured, sometimes a couple foot high in the mid 60's and early 70's. The stench was horrific. As those with million dollars shacks along the shoreline started complaining to our DNR, they re-introduced salmon into our Great Lakes. The annual die off of these bait fish is what prompted our DNR to re-introduce salmon back into the Great Lakes. This was originally done in the mid 1800's and periodically over the years, but in the late 60's when the annual die off of alewives caused them to double down on thier restocking efforts. Because of the large number of bait fish in the Great Lakes, these salmon grew large and fat off the abundant supply of bait fish. A multi-million dollar fishery was born. I'm proud to say I've been in on it from the start.
Doctor Howard Tanner and Dr Wayne Toby were the two biologists from MSU that our DNR turned to, to get these salmon re-introduced to the Great Lakes. As a sidenote, one of our roommates when we first moved from our parents homes was the daughter of Dr. Wayne Toby.
They got some of the first plants from fish that came from Washington State and Alaska. A budding fishery that made millions in revenue for the State, not to mention the sales of boats designed for Great Lakes fishing.
