just for fun I went to canon's blowback chart and checked 100' of line out with 8, 10, and 12, weights, and the depth shown for the 8 and 10 was 100' down. the 12 was just a couple of feet deeper. but that's at 2 mph. Another example they gave was at 4 mph and the depth was only 80' down. but this is a far cry from losing 15' down 30'. just go to cannondownriggers.com and check out the blowback on the charts for yourself then you will have a better understanding of blowback. so I figure with the 10# dredge weights at 55' with a deep diving bandit my lure should be close to 60' deep at 3 mph. works for me. I figure at 2 mph you are still right on and at 4 you lose 20' at 100' then at 3 mph you should only lose 10' at 100'. but then cut that in half at 50' you should only lose 5' at 3 mph. so at 55' the weight should be at 50' then with a 30' lead off the weight I figure I'm gaining another 10' which puts my crank at 60' with fish at approximately 65' which puts my bait just above the fish and anyone that knows about walleye known they mostly feed up but not always.

sorry for both lengthy posts., but I'm just trying to help the op as much as I can. and by going to cannon he doesn't have to depend on anything I say.