The school of 'gills was suspended off a sandy ledge in 12 feet of water. Once I'd located the fish it was a simple matter of catching them later with weighted nymphs, and we boated all we needed for several fish fries. Always fish nymphs slowly for bluegills. Small, stunted bluegills carelessly rush almost any type food, including nymphs. But big bluegills are slow, deliberate feeders.
Strikes usually occur as a nymph is motionless, or slowly sinking.
Many novice fly-rod nymphers have trouble detecting bluegill strikes, particularly when working water deeper than 6 or 8 feet. This is the art of nymph fishing. It takes a sort of practiced sixth sense to know when to set the hook. Often a nymph intended for bluegills scrapes bottom or rubs against a weed or other obstruction, sending a light signal up the line and jangling your nerves. But with experience you'll learn to separate these from signals transmitted by taking bluegills.