Place the fish in a large non-metal dish. Whisk together the 6 tbsps oil, orange zest, orange juice, ginger, hot sauce and salt and pepper. Pour over the fish.
Cover and marinate in the refrigerator for 30 to 60 minutes. Meanwhile, prepare grill. Brush the fish with additional oil. Grill until fish just flakes when tested with a fork, about 5 minutes per side for each inch of thickness.