Last year we did this whitewater rafting trip out in western MA. They actually organize a full Whitewater MB class, but we wanted the kids to have an introductory run first before getting into the whole MB requirement process. It was on class III rapids which I thought were pretty mild (albeit, it was a dam release river and I don’t think we got the benefit of a huge rush of water). These kind of trip can be a little on the expensive side ($65-$100 each), but they are worth it. Every kid wants to do this activity. We did ours in early June and wore wetsuits, which was perfectly fine. Here’s a link to the MB program offered by the company we used:

 http://www.crabapplewhitewater.com/group_outings/scouts.shtml

Here’s a few up in Maine:

http://www.neoc.com/content/4033/_Girl_Scouts/

http://www.proriverrunners.com/index.php?page=scout_badges

http://www.adv-bound.com/

scout-whitewater-badges.pdf

These kind of trips are run all over the country. Here’s a couple in PA:

http://www.laurelhighlands.com/activities/meritbadge.html

http://www.wilderness-voyageurs.com/whitewater_merit_badge.htm

You’ll need to google whitewater MB [your state] to find local ones.