BASE Jumping The Trench Line: Wingsuit Proximity Flying by Sebastian Alvarez Posted by Andrew R. ShareTweet 30 Oct Video can't be loaded: Sebastian Alvarez Wingsuit proximity fly. TRENCH LINE. Sputnik Exit. (https://www.youtube.com/watch?v=37YROdTDfOU) Check out Sebastian Alvarez’s wingsuit flight as he squeezes through the Trench Line off Sputnik exit in Switzerland. Word.