By late winter, the tuna move far offshore, into the Gulf Stream. Rooks takes his parties as deep as 3,000 feet, 50 to 60 miles out, in search of bluefin. He looks for schools of tuna surfing down the waves, or big flat spots and slicks on the surface. He also watches the fish finder for clouds of bait and tuna. “I’ve seen schools of tuna that were 2 miles long,” he says.