With my rod tips only a few inches off the water a 1/16th running at .7 mph is running about 9'-9.5' deep an at .9 mph theyre about 7'-7.5'deep. Everybody's MMV depending on their setup. If the fish are sitting deeper (15') I'll either add a split shot the size of a 1/16th jighead to each line or I'll pull double 1/16ths at .8-.9 mph. That will get them down to about 13' deep. 1/8ths would probably do the same thing but I dont have any and havent "learned" how deep they run.