there's a small stream that I fish regularly which has a couple of holes in the 10-15" depth range. Around Christmas I was fishing one of them and having no luck until I finally got to 6 (!) split shot above a rust wb and pt nymph. Once I got enough weight on it was game on. The fish were laying down there deep and it took a bunch of weight to get to them. I used a 3/4" thingamabobber to hold the monstrosity up. The thingamabobber was about 2 feet up my flyline. Casts were just flops upstream to the top of the hole. Just my limited experience.