 Bob Gale (qv) explains that, to find a coordinator for the  skateboarding scenes, he went to Venice beach and approached two  skateboarders. One turned out to be European skate champ,  Per Welinder (qv), and the skater he was with became the stunt  double for Eric Stoltz (qv), but was recast when they recast the  role of Marty McFly in order to match Michael J. Fox (I) (qv)s  height.