This video was put up on youtube by friend of R2T Eric Campbell, who runs http://www.techrescueblog.com/. The video shows an edge transition of a basket and an attendant that is being attempted without the use of a High Directional (HD), such as an Arizona Vortex (AZV).
While there are a few techniques out there that make transitioning an edge like this possible without an HD, it really is in the best interest of clean, safe rigging to keep your ropes off of an edge. While the edge attendants made a valiant effort and did in fact get the rope in the edge rollers, the edge rollers had moved over the edge and were non functional.
I’ve had many an argument where I work about whether or not we needed to purchase something like an Arizona Vortex. It took a few years and a couple of incidents’, but the case was finally made and we now have several. The horse is at the water, maybe he’ll drink after seeing this: