One of the keys to the success of the programme is the course is always made up of a mix of teenagers with quite different strengths and weaknesses.
A typical Cactus course will have a cross-section of students, from some of a school's best students right through to some who are really struggling.
The programme is designed to challenge a young person physically and psychologically " with a focus on teamwork, goal setting, discipline and leadership development.
It is always very encouraging to talk to the parents of the teenagers who attend Cactus and hear their stories about what a life-changing experience Cactus has been for their kids. Comments such as "I've got my boy back", or "They have such a better attitude at home now"; or "I don't think any of us ever thought they would achieve something like this" are pretty typical of what I hear after every Cactus course run by the Rotorua team.
Similarly, the feedback the course instructors receive from the students who attend the course is also pretty special.
And that is why I am not surprised that so many police officers volunteer their off-duty time to assist running these courses.
Just about every police officer I have ever met joined the police to make a difference. It is a characteristic that has become one of the strengths of our organisation. The police is full of people who are passionate about what they do and come to work every day to serve their community and help others.
Authentic leadership.
Nothing gets done without it. More on that next week.
Inspector Bruce Horne is the Rotorua police area commander.