I am by far no expert at this but from what little I know, I will say this: First you didn't say what size ball you are running so with that I would say. All weights have to be run deeper than 50' to fish your lure at 50' due to the bow in the cable that is created by trolling. How much deeper depends on ball weight, speed, wind direction, current (even in a lake). Now again you didn't mention what kind of lures you are fishing so say you are running a flutter spoon it doesn't really sink or dive much it runs pretty flat so if your ball is set and running at 50' the spoon will be close to the same. Now if you are running a crank bait you might have to add the depth that the crank bait runs to the ball depth. Say the crank bait runs 12ft deep you might want to start running the ball at 38' to get the bait down to 50'. Again this has a variable also because the crankbait diving depth varies on line size and amount of line behind the release on the ball. Until you figure this out one thing most anglers who use downriggers do is run stacker's They will allow you to run diffrent rigs at diffrent depths on the same cable. But be aware that you do not want to run diving baits above flat running baits this will only bring on a massive headache in tangles run the deeper diving baits on bottom and work you way up the cable to flatter running lures also as you put lures higher up the cable shorten the leader length from the cable to the lure this will help keep the tangles down as you make turns with the boat or change speeds. As far as how far you run a lure behind the release, that all varies with what kind of fish you are fishing and with water clarity or how spooky the fish are. The fish will let you know by slamming the lure what they want. Experamenting with this is your guide I have heard on some lakes you need to drop back as much as 200' some times only 10' will get fish. If you know of someone who has fished this way before invite him out with you to show you the ropes on this kind of fishing, learning from a experienced angler will cut down on a lot of time learning it just by yourself. Also as you learn this new way of fishing keep a log so when you get home you can look over what you did that day and the next trip out you can add more things methods to what you did that day or go back to the things that worked. There are many more guys on this site who fish with riggers and should be able to help you out more with this, I just thought I would give you a small insight of what you need to know.
Cold Feet
