In the soft glow of the oil rig's lights, barely perceptible at the limits of its golden arc, white water exploded. Dozens more eruptions followed immediately, and in seconds the calm, dark water 50 feet aft of the charter boat Strike Zone came alive with miniature geysers. "They're here!" roared Capt. Kevin Frelich as he quickly snatched a ready rod. With a long, spiraling cast, he dropped a bait near the patch of boiling water.