As per the scouting rules fixed blades are out of the question, now my local council also doesn't allow anything without a lock, so I will also go by that. Finally, I know most scoutmasters get scared of anything over 4" or Assisted opening. So, my suggestions based on that are:

1. Benchmade Monochrome (for an inexpensive, but extremely high quality and good sized single blade one handed folder)

2. Victorinox Locking Swiss Army Knives, also called Victorinox Pocket Tools. (They have a lot of usefull functions and are pretty inexpensive, however not as durable as the Benchmade)

It would be good to know if you have any restrictions (length, lock, fixed blade, ect), that way we can narrow our search down (or expand mine).