Another great day fishing on board the Big Eye II, with Captain Franklin, Yellowfin tuna in Costa Rica can range in size, with some individuals weighing over 200 pounds. However, the average size often encountered by anglers is in the 20 to 60-pound range. today we caught 8 yellowfin tunas and we landed one huge tuna of around 140 pounds, we fought that fish for about 2 hours, it was great sashimi tonight, check more reports from Captain Franklin