Trolling for Trout

Question
Regarding the depth of my lure, I have found a lot of information about how deep to troll, experimenting, speeds, weight, etc.  Every article I read says something about "until you reach desired depth".  Nothing I've been able to find, however, answers my pretty basic question:  How do I know how deep my lure is?  Can you?

Answer
Hi Rob,

The hard core trollers do a lot of research with lures to determine how deep they are going.  For instance, find a part of the lake 20 feet deep and keep letting out line till the lure starts bumping the bottom.  Then record that length and speed.  Find a spot 10 feet and do the same.  Now you can interpolate in between.  

The books with the dive charts for the specific lures take away all this figuring.  They have done the work.  In fact they actually put a diver in the water to observe depths.

Then there are things like lead core that have been designed to go down about 5 feet per color.  A full 10-color lead core (100 yds) will run about 50'-55'.  

To answer you question, it is all about experimentation and record keeping.  There is no magic formula.  The dive charts are great but they haven't been done for all lures.  Here on Lake Michigan, there are other factors like underwater currents that can make things run deeper or shallower.  A lot of people think that trolling is just tossing some lures out the back and driving around.  No so.  Successful trollers are real technicians.  

Good luck,

Marc