Gray's Reef National Marine Sanctuary, Georgia

One of the most popular diving areas off the Georgia coast is Gray's Reef, named after Milton B. Gray, a biological collector and curator at the University of Georgia Marine Institute, who studied the area during the 1960s. The area is one of the largest near-shore live-bottom reefs of the southeastern United States. The sanctuary is 17.5 nautical miles (32 km) off Sapelo Island, Georgia, and encompasses 17 square nautical miles (58 sq km) of live-bottom habitat.

Sandstone outcroppings and ledges up to 9 feet (3 m) in height separate the sandy, flat-bottomed troughs in a reef that combines temperate and tropical qualities. The rocky platform, 60-70 feet (18-21 m) below the Atlantic Ocean's surface, is wreathed in a carpet of attached organisms and is known locally as a "live-bottom habitat."

The sanctuary headquarters and interpretive center are at the Georgia Marine Science Center on Skidaway Island near Savannah, Georgia.

Lodging, dining and other amenities are available in Savannah, the closest city to Gray's Reef National Marine Sanctuary.

Depths: About 60-70 feet
(18-21 m)

Visibility: 20-30 feet (6-9 m)

Water temperature: A wet suit is recommended. The area has temperate climate with a seasonal mean temperature of 51 degrees Fahrenheit (11 degrees Celsius) in winter, 66 F (19 C) in spring, 80 F (27 C) in summer and 66 F (19 C) in fall. Frequent thunder showers moderate summer temperature.

Aquatic life: More than 150 species of fishes including black sea bass, snapper, grouper and mackerel are attracted by the reef. Larger creatures like barracuda and nurse sharks ply the fertile waters. Algae and invertebrates grow on the exposed rock surfaces; dominant invertebrates include sponges, barnacles, sea fans, hard coral, sea stars, crabs, lobsters, snails, and shrimp.

Fees: None

More info: Call the sanctuary headquarters in Savannah at (912) 598-2345 or visit http://graysreef.noaa.gov.

Open: Year-round.

Getting there: Divers can easily reach Gray's Reef Sanctuary from numerous marinas and boat landing facilities along the coast between Savannah and Brunswick, Georgia.