Great reply Ruger! Point of entry or distance behind board dictates lure depths.Along with lure size & line diameter used.Pulling a multiline spread can take some getting used to.Here is how I try to break it down as there are quite a # of ways to acheive desired depths or spreads.Reading your electronics to determine the depth fish are located at might come first.This determines lure types & sizes as well as line types…IE mono,hardline or leadcore.Then figuring out preferred lure body style & colors.Once you have these figured out its game on!I will give a couple examples.
Two identicle lures such # 7 Shadraps can be pulled side by side at same distance back,lets say 100′ if you are using different line types in similar lb test such as mono on 1st rod out & braid on the second.The difference in depth is about 2 feet.Here your looking more at line angles or dive curves in the water.You put a #5 & #7 Rap same distance back both with same line diameter,again different line angle or dive curves.If your looking at running all lures at same depth then distance back from rod tip or board is key.Thats where the trollers bible helps in that learning curve.
I will generally pull a V through the water column either above the water & or below on a spread until I might have something pinned down. I could give more examples or possibilities of a 8,10 or 12+ line what I call family set I use here in WI a bit later if interested. Chaos at its finest!