Howdy,
Fishing the summer hole on the Sky. with good numbers of fish that have become uninterested, I watched James (if you fish Reiter during the summer you probabaly know who he is) get his limit and lose a couple in short fashion. He fishes the other side of the river so I had to ask. The technique is a 3-2 shot slinkie, at least 7ft. leader and a small tuft of yarn in the bait loop. Another current post is discussing lining of fish, and while this set-up could line fish in situations the summer hole is quite deep coming through a large boulder on shore and another mid-stream. Low flows put the ixnay on a good drift, so what the trick is the long leader gives you a microdrift once your tiny weight anchors. Yarn color changes, what worked yesterday won't today is the rule of thumb.

Several years ago, on the S.F. Stilly in a hole called Swiss Cheese I did some study on the couple dozen Summer Steelhead which held there during low flow. Guaranteed first cast fish-on holes are what makes all the leg work worthwhile. Getting another take here seemed impossible, so I decided to see what it would take by going lighter and lighter on my line test (I also started casting off the top off the cliff in order to see the reaction) A nightcrawler on 4lb. with no weight would slowly sink past the suspended fish nearly reaching bottom when one of the fish(not always the same one) would race over sniff the worm then fin back to where it started. Heres the kicker, take the same crawler and chuck it by itself into the pool, and the same result except the fish would eat it. My conclusion is fish do know when line is involved and sometimes care.