This is a tough one.  As a general rule, I like to have my students perform the exercise with as little interference as possible.  I do enjoy role playing as the victim though and this provides me a unique perspective on the drill.  You may need to step in to clarify a technique on occasion.  We will often demonstrate various skills before having the students perform.  Always ask yourself if your involvement is necessary to further learning or not.

I do provide several really challenging scenarios/exercises.  These really challenge my helpers and students and make them think.  Often, my helpers are included as extra participants in scenarios in the more difficult roles.  This can be fun and very instructive for them and the students.  This is also a great recruitment tool for helpers and eventual instructor candidates.

As discussed previously, an instructor needs to watch the whole evolution.  This is for safety as well as the debrief afterwards.  If you notice any unsafe activity beginning to take place, warn the student and explain immediately.  You can also quiz the students for alternative approaches.  Add hypothetical changes during your talk if that helps as well.  Our goal is to get everyone thinking, asking questions, and learning how to best use their training.

For some exercises, I like using video and then playing the scene back.  In the heat of an exercise, things happen quickly and sometimes without thought.  Video is great for capturing subtle mistakes that can easily be overlooked.

<p>Having a helper or assigning the role of a helper to a more advanced student is a very important safety factor.  They can be a victim or provide a watchful eye for any unsafe activities.  The lead instructor needs to be able to watch everyone so they can evaluate the overall actions taken.  This is necessary for the debrief.

A key safety factor is the "For Real" signal.  This can be the standard 3 whistle blasts or something else.  At this point, the exercise is over and a real rescue is begun by qualified personnel.  Go over this protocol with your students and helpers before starting any scenarios.

I like to work in scenarios throughout my class - keeps them guessing ;-)  When a new topic is taught, add a hands on exercise to reinforce.  Students love the numerous exercises.  If you have lots of helpers, they can stage the incidents while you or another instructor are teaching.  This keeps the class moving along.

Make setting safety below part of every scenario - really drill in this concept.  When working with ropes, ensure one student is above the accident scene as well.

Don't forget to bring the first aid kit so you are perfectly ready in the unlikely event of an injury.

As instructors, we can potentially teach this class on a wide variety of levels and duration.  Our students can be quite young or elderly - often a mix.  Some students are rock solid class V boaters, others are novices.  I like scenarios that require a team effort and proper use of the various skill levels at hand.  This enables me to challenge the seasoned veterans (they can take the role of an incident commander) as well as the less experienced individuals.  Breaking into reasonable sized teams can help ensure everyone gets practice.

One exercise I really enjoy staging is a foot entrapment on the opposite river bank in a nasty class IV rapid.  I have lots of extra help to prevent any unsafe activities.  This type of scenario takes lots of bodies and coordination.  It reinforces a very wide variety of skills and does a great job at simulating initial confusion - something that is common in many rescues.

The classic yard sale with multiple boaters is simple to set-up anywhere and helps ensure everyone gets a turn.

I highly recommend reading the American Whitewater Accident Database for more recent incidents and constructing scenarios based on them.  This keeps the course very relevant and aids in the debrief after each exercise.