The Rapala DT Series is a great example of a search crankbait

The key to using a crankbait as search bait is to have your GPS or buoy ready.  If you get a bit, mark that spot.  There was a reason that fish bite you there.  Chances are that more are in vicinity, if not on the same spot.  Cast all around after catching a fish and note any differences.  Maybe there is an underwater point, rocky hump, inside weedline, or so on.  All these items can give you a pattern that the bass are on.  Take what you learned from that first catch and use it to your advantage at the next spot.  Find another location that has the same structure.  You should be able to reproduce the same success in other locations.

 Two of my favorite crankbaits to use are the Rapala DT 16 and the Rebel Wee-R.  The Rapala DT Series allows me to cover a vast amount of deep water.  Pick this lure when your hitting weedlines or edge of weedlines in 10 to 12 feet.  Anything shallower and you will hang weeds up way to often.  The Rebel Wee-R crankbait is great for fishing over shallower water, in the 8 ft or less range.