all a downrigger does is hold your bait/lures at a depth you set
so when using lures you can get bib less lures and run them at the exact depth you want them to run
you can run the boat at any speed you want as the lure isnt doing the work of keeping it at depth the downrigger is
if you use lures that dive you just need to work out how deep there diving on the own then lower the downrigger to the depth you want to fish at
downrigging is a great way of catching flattys on lures
simply use a lure that will dive about 2mtrs then set your bomb about 2mtrs off the bottom
as you troll around the lure is going to be hitting into the sand and puffing up sand grabbing the flattys attention