Put the Mahi Mahi in a glass dish and pour the marinade over the fish. Make sure that the marinade is evenly distributed over the fillets. Refrigerate in marinade for 4 hours.
Spray the grill with vegetable spray to prevent sticking and preheat on medium heat.
Take the Mahi Mahi out of the marinade and put on a rack to let some of the marinade drain.
Grill for 4 minutes then flip each fillet and grill for an additional 2 to 4 minutes, depending on how thick the steaks are.
Remove from grill and place on platter. Serve hot.