A great Troop Meeting idea centers around fly fishing.
Scouts gravitate to adults who are really into a unique and intricate hobby. Fishing is good. But any idiot can pull a catfish out of a pond with blood bait. Fly fishing is distinctly different.
I’m not a fly fisherman. So I can say with confidence (and immunity) that fly fishermen are bat-crap crazy. They are really into what they do. Casting is intricate and requires tons of practice. No fly fisherman is ever satisfied. They want to learn, get better, and innovate. But before they innovate, they want to learn the old ways. Most fly fishermen that I know own at least one very old rod and at least one very new one. Any rod beyond its useful live becomes a wall ornament.
And they tie their own flies. At least the true ones do. This requires and explanation – and demonstration – to show what the fly looks like from underwater. (Only a flying fish would care what it looks like from above.)
Get an aquarium and put it on a glass table or old milk crate turned on its side so that scouts can see the fly from underneath. Have another station outside where scouts can learn to cast. Another where they tie a fly. And one explaining trout, salmon and other fish types commonly targeted.
Plant the idea with the SPL. Let the PLC find the fisherman and organize it.