In this DVD Vertical Rope Skills Master Douglas Hansen addresses the primary skills
This is a 1 hour and 10 minute DVD that covers many of the skills used by anyone who ventures into the vertical world. Rappelling, Climbing, Caving, Ice Climbing, Rope Rescue, Rope Course skills, Rope Access, Industrial Rope Work, Safety, and even skills that are used in fall protection and fall recovery
The quality of the DVD is much better than the sample below. This is the best transfer I had, as time allows I will see if I can make it better quality. Also, the above diagram of the Hedden knot shows a two wrap and the completed one shows a three wrap. I teach students to tie a Hedden and a Prusik with three wraps; sometimes two wraps will slide.