Lake Hamlin near Ludington, Michigan.  In the summer the smallmouth hold down in 25-30 feet flats off the break line.  I've caught them drifting a 3/4 oz jig tipped with a leech or gulp combo.  Is there a way to vertically jig when there is no current?   I do this on the detroit river, but there is current and you just follow your line with the trolling motor as you move down the river, but what do you do when your on a  lake?  Seems like your line would just stay in one spot.  Maybe use a heavy jig and just use the trolling motor to move?

How about Carolina rig, drop shot, swimbaits?  I don't fish that deep very often.

Try a 3/4 oz Ledgebuster Single Willow Blade spinnerbait. Cast out

over or just beyond structure and allow the lure to fall to the bottom.

Lift the Ledgebuster with your rod from water level to 12:00, then fall

on slack line. Repeat back to the boat . You want the lure to flutter down

like it's dead, NOT moving forward.

Be careful. This is a big bass lure and you might get your arm broken

or be jerked out of the boat!

Good luck!

8-)

This is a very good smallmouth fishery.  Off the breakline you can also try dropshotting gulp leeches or creature baits.  I would not go heavier than 8lb flouro.  Hang On!!  

I like RW's suggestions - if you don't have a 1' grass coating on the bottom at that depth, which does occur on many types of northern lakes. If you are not bothered by that, then the Ledgebuster is a great option. Along with 3/4 oz. blade baits.

However, current or no current, it'd be very hard to beat a drop shot on any body of water. IMO!