Prepare Gingered Pineapple Marinade by mixing all ingredients. Remove 1 cup of the marinade; cover and refrigerate remaining marinade for basting. Cut fish into 4 serving pieces. Place fish in shallow glass or plastic dish. Pour 1 cup marinade over fish. Cover and refrigerate, turning once, at least 2 hours but no longer than 12 hours.
Generously spray grill rack with nonstick cooking spray before heating grill. Heat coals or gass grill. Remove fish from marinade; discard marinade.
Cover and grill fish and pineapple about 4 inches from medium heat 8 to 12 minutes, brushing frequently with reserved marinade and turning once, until fish flakes easily with fork. If pineapple becomes too brown, remove from grill.) Discard any remaining basting marinade.
Makes 4 servings.