When you stepped onto a Lake Michigan trolling boat several years ago, chances are every reel onboard would have been spooled with identical nylon monofilament line. The skipper probably bought the line in bulk spools and changed it frequently. That’s all changed. In fact, if you board a boat these days and notice the skipper relies on only one kind of line, you might want to reconsider your choice of captain.

There are dozens of kinds of fishing lines available these days, each with one or more attributes that put them a cut above all the others for certain uses. Great Lake trollers who are on the cutting edge know what’s available and how to use those products to their best advantage. When you step onboard with these guys, you’ll see reels spooled up with a variety of lines, in several colors and in different strengths. Some reels will even be loaded with two or more kinds of line.

Here’s a strategy often employed on the reels used with directional diving planers. Start with 30-pound-test monofilament. Fill the spool to approximately two-thirds capacity with this backing. Set the line counter to zero and meter on 150 yards of one of the gel-spun polyester lines, also 30-pound-test. Any of the popular brands will work, but the ones with a “slick” finish tend to be more resistant to fish-hook fleas, common most years from midsummer into the fall. Finally, set the line counter to zero once more and spool on another 100 feet of 30-pound high-visibility monofilament. A double Uni-knot makes a solid connection between the mono and the polyester line.

The top length of monofilament is for early-season use when anglers want the divers to get out away from the boat as much as down deep to the fish. In early season, Great Lakes salmon and trout can be reached by spooling 20 to 50 feet of line but never more than 75 feet. Let out more than that and the inherent stretch of the mono makes it tough to trip the diver and the 3 to 1 dive ratio obtainable with shorter lengths of line becomes something like 10 to 1. The drag of the relatively thick mono pulling through the water means you’d have to let out 10 more feet of line to get the diver 1 foot deeper.

Once the fish go deeper and the divers need to get more than 20 or 25 feet down, discard the monofilament and tie directly to the polyester line. The thinner diameter and nearly zero stretch will allow conventional divers to dip down to 50 or 60 feet easily and even deeper by using oversized add-on rings or magnum divers.

Why this obsession with 30-pound-test? The reason to fish the Great Lakes is to see how many trout and salmon you can catch -- not to see how many divers you can litter across the lake’s bottom. Diver line less than 30-pound-test just doesn’t cut it. You can lighten up the leader between the diver and the lure as much as you wish. But make sure it’s 30-pound-test or more from the rod tip to the diver.

BLOWBACK STRATEGY
When trolling, forward water pressure on the downrigger weight, downrigger cable and fishing line all team together to cause what is called “blowback.” A trolling angler might have 80 feet of downrigger wire deployed, but because of the deflection, the downrigger weight is only 60 or 70 feet beneath the surface. The deeper one attempts to troll, the more guesswork is involved because of blowback.