I think the the only way a skydiving movie will be successful in the main stream market is if:
A> Jessica Alba or equivalently hot lead character
B> Sex appeal, romance, and adventure
May be she wants to get revenge on the bad guy for killing her father and she steals his money by airlifting a safe, cracking it and jumping out without getting caught.
A mix b/w the italian job, blue crush, and into the blue? There's got to be a story line and skydiving is a major part of it...but not the only part....