Where I fish for kokanee the lake has deep drop offs close to shore...in some area's it's well over 100' deep within casting distance. I haven't tried this...but I don't see why it wouldn't work. Cast a small lead jig out and try to figure what depth their at by letting the jig drop and doing different counts before jigging it back in. As far as the kokes in the creek mouths this time of year, their busy spawning.