If the fish are at 17 feet, select a lure that runs deeper. Using lighter line will increase the maximum depth the lure runs to a certain extent. Letting out more line also helps squeeze a bit more depth from a lure, but again there's a limit. Letting out too much line actually has the reverse effect, producing a bow in the line that creates drag and reduces the maximum running depth. A faster troll or retrieve will get the lure to its maximum depth faster.
Action can be an important consideration.
If one action isn't working, try a lure that has a different look. Color can make a difference. Water clarity and light conditions will dictate which color or color combinations are most visible to the fish. Always experiment with colors. Silver and gold-finished lures seem to work well in clear water.