Great Bay, Australia offers 1 beach perfect for sunbathing, surfing, swimming, and more. Great Bay, Tasmania, Australia, is known for Bruny Island Cheese Co. and Get Shucked Oyster Farm. The best time to travel to Great Bay, Australia, is during the summer months of December to February, when the average air temperature is around 70-80°F (21-27°C) and the water temperature is approximately 68-72°F (20-22°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!