Batt Reef is a coral reef off Port Douglas in Queensland, Australia. It is centred at 16°24′S 145°46′E and is part of the Great Barrier Reef.The reef is about 18 km long by 5 km (11 miles by 3 miles) wide, lying northwest to southeast, at the northern side of Trinity Passage that leads from the inner Reef channel from Trinity Bay to the Pacific Ocean.