It's not a Westsail or even a Colin Archer design, but Archer's family was from northern Scotland where they had Zulu's and Fifies--double-ended workboats that likely have Norweigan heritage. Anyway...I came across this video of a restored 70' Fifie sailing at 15kts.  Amazing, especially last third of the video where it really flies.

http://www.youtube.com/watch?v=STq2_CM7os8&feature=mr_meh&list=UL5iSBStvkK78&lf=mfu_in_order&playnext=0