Onlookers also cheered for John Petruescu, the angler who caught the whopper during his first long-range fishing excursion to the giant tuna grounds, deep in Mexican waters.

Before Petruescu's catch, at remote Hurricane Bank after a two-hour fight, a 427.9-pound yellowfin caught last April off Puerto Vallarta had been the largest.

"People on the boat were telling me they've been fishing on these long-range trips for 20 or 30 years and have never caught a fish like this," said Petruescu, 33, of San Diego. "All I knew after catching it was that this fish was big."