Hope you have a great time hiking. I go with our Scout troop about once a month, and it gets easier after a while, really <img src="/images/graemlins/grin.gif" alt="" />

A couple thoughts on the list you had:
- Although you don't necessarily "need" food for a short day hike, I would suggest you always bring some. The water is more important obviously, and you have it covered. The food is more for a psychological boost on a day hike, especially if you have a steep area, or a rough stretch of weather. Also, it's nice when you reach a goal, like a summit, or are just taking a break, to pull out an energy bar, some trail mix, or pemicin. Trust me, you'll have more fun hikes if they all have some simple snacks. On longer hikes in cool weather, we make sure they all bring a cup, and one of us adults brings a lightweight stove to heat up water for cocoa.

- You mentioned a poncho or garbage bag, I would also recommend that they bring or wear an insulating layer, like a fleece jacket or pullover.

- Along the same lines, make sure they all are wearing clothing appropriate for the conditions. If you're hiking, make sure they have reasonable hiking boots, with decent wool/synthetic hiking socks, not cotton athletic socks. Liners are great too, and will help avoid the blisters for the newbies.

- Insect repellant is pretty important in some areas. In the northeast, we have mosquitos and ticks to contend with. It can really put a damper on your trip if you don't have it. You can lather them up before the trip, and then have them carry a couple of the insect repellant towelettes to refresh after a lot of sweating.

- Sunscreen and sunglasses, if appropriate for your conditions.

- Make sure that they have some blister related items in their FAK, like moleskin.

- You might want to have one or two people, or a leader, carry some sort of bivy sack. If one of the boys falls into the water, or should get hurt and need to be still until you can get help, it's good to be able to keep them warm.

I'll think about it more, but, those are things that come to mind right away. Have a great trip!