An intrepid crew of U.S. yachtsmen evades Poseidon in a spot that ESPN is running to back its coverage of the America's Cup on ESPN2. The special effects are more B-movie "Jason & the Argonauts" than state-of-the-art "Star Wars"; other spots feature a giant crab and the song of the sirens. The mariners' quest, under way this month, is not for the golden fleece but to regain the Cup from New Zealand. Ground Zero, Marina del Rey, Calif., created commercials, running on both ESPN and ESPN2. Copywriter: Tyler Hampton. Art director: Paul Foulkes.