Perfect Cast
I have seen both of Henrik Mortensen's DVDs, and they are superb.
His first DVD, "The Perfect Cast," is as concise a presentation of the Underhand casting method and fishing technique as I have seen. Filmed in Iceland, the fishing sequences--particularly those of salmon rising to a riffling hitch--are some of the best on film.
As no U.S.-based Forum Sponsors presently carry either of Henrik's DVDs (that I know of), I believe that I can recommend Western Rivers Flyfisher in Salt Lake City (1-800-545-4312). WRF is a superb "Spey" Shop, and sells "The Perfect Cast."
If you are in Canada, I believe the Forum Sponsor Whistler Flyfishing also sells "The Perfect Cast."
At this time, Henrik's second DVD "Distance & Delicacy" is only available in the PAL format, and will NOT work in most North American DVD players (unless you have a region-free DVD player).
Henrik's first DVD, "The Perfect Cast," is in the NTSC format, which IS compatible with North American DVD players.