http://www.wimp.com/mastbridge (Could be little haroowing with a narrow(ing) bridge opening. ;^)))
But while you're at it -- try an ultralight maxi under a lower bridge opening
Part I - http://www.youtube.com/watch?v=jXHsNmQehr4&feature=player_embedded
Part II - http://www.youtube.com/watch?v=SNjI0aB1AgQ&feature=relmfu