hitman,when you say u get 5-6 ft. for every 10yds,what speed is that based on.I know with 18lb leadcore I get 4-5' with 10yds. @ 2.0mph on my gps.pretty consistently through my own testing.I know the manufacturer says 5-6 ft. with 10yds. out of copper but it does not say what speed that comes from.I thought maybe since it is probably being used more for salmon on lake MI and lake Ontario that it is more like a base speed of 2.5 or so,if that is the case I typically troll from 1.5 up to 2.5 with average of say 1.8-2.0 that would mean maybe 6-7 ft. of depth with copper @ around 2.0,which would mean copper would be more effecient for me....thanks for the response...