This is a very instructive and simple video. It lays out a very good foundation for anybody wanting to learn to cast, mend, and fish Scandi style with one or two hands with a strong emphasis on bottom hand.
Klaus Frimor gives a very simple and straight forward description of what I take to be Scandinavian Spey casting, or possibly the underhand technique.
I am working on some drone footage of yours truly flailing away in an attempt to master my underhand technique. One thing I have learned is that it really has helped me to use a fairly fast, stiff-ish, if even “tippy” rod to cast true Scandi style. I will soon do a review on my favorite rod for Scandi Spey casting with an emphasis on the bottom hand. Here is a review on the my favorite line.