They should be going pretty shallow, preferably near some kind of inflowing current. Who knows what depth they're suspending at, if you had electronics, that would help, but since that's a no, start at the bottom and move up. I would jig for them with little tiny jigs tipped with maggots, barely even moving the lure. If you know where structure like weeds or timber is, fish there. I'm no Wally Marshall, but that's the best that I know. I know there's crappie fishermen on here, and I'm not one, just thought I'd tell you what I know.
-Wes