Note
US CMO Champs -- Trail. I took my best shot at it from the platform, ad my angles were pretty good, but the answers are really sensitive to distance errors, so I didn't fare very well. Part of the secret may be to try and think like Peter, to figure out what locations he's likely to have chosen.
The deal with my balloon contraption was that I brought the camera rig into the party store at 1:30 PM, and two dozen balloons was enough to lift it, so I bought a extra half-dozen (and one popped). By 7 PM, I cut off a lot of the extra strings to lighten the load, but the balloons had lost enough helium that they wouldn't lift it any more, even after I removed a strut to reduce the weight. I had thought about mylar balloons instead of latex (helium diffuses through latex pretty fast), but that would have been quite a bit more expensive. My other plan, which might have worked, was to buy a small helium tank and use it to fill a trash bag just before using it. A major issue is that party balloon helium contains some air (maybe 20%?); it's not intended for lifting things, and any more would be a waste. (I had suspected the helium content was even lower, but that's what I found on the web, I haven't done the math yet.) I know it's possible to get pure helium at a higher cost. It's also possible that the drop in temperature from the afternoon to the evening adversely affected the buoyancy of the balloons. I think the general design was pretty good, and it would have been nice to at least have the chance to see what the video quality looked like. Probably worth trying again if the winds are calm next year.
Since I couldn't do anything else with the balloons, I just left them floating over the barn on their dental-floss tether during the night-O, but they escaped somehow.