With less than four days left in the North Atlantic bluefin tuna season, the fleet races to claim the title of Gloucester's top-earning bluefin boat. But with two top contenders, last season's champion Captain Dave Carraro of the FV-Tuna.com and previous top-earner Captain Tyler McLaughlin of the Pinwheel, potentially sidelined, the field is wide open and it will all come down to the last fish.