These big, tough bungees are designed for one purpose: hucking willing human beings across their surface of choice, be it asphalt, concrete, rails, snow, ocean spray, or river current. The promise of easy speed seduces surfers, skimmers, skaters, longboarders, urban jibbers, skiers, snowboarders and riverboarders alike into a torrid affair with the lithe black beauties. In a post-adrenaline haze, the smitten cast aside boats, ramps, lift tickets and other yesteryear propulsion devices like last weekend’s post-kegger hookup.