Hell Gate is a narrow tidal strait in the East River in New York City. It separates Astoria, Queens, from Randall's and Wards Islands.
A cay, also spelled caye or key, is a small, low-elevation, sandy island on the surface of a coral reef. Cays occur in tropical environments throughout the Pacific, Atlantic, and Indian Oceans, including in the Caribbean and on the Great Barrier Reef and Belize Barrier Reef.
A tide pool or rock pool is a shallow pool of seawater that forms on the rocky intertidal shore. Many of these pools exist as separate bodies of water only at low tide.
Phosphorite, phosphate rock or rock phosphate is a non-detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite (or grade of phosphate rock) varies greatly, from 4% to 20% phosphorus pentoxide (P2O5). Marketed phosphate rock is enriched ("beneficiated") to at least 28%, often more than 30% P2O5. This occurs through washing, screening, de-liming, magnetic separation or flotation. By comparison, the average phosphorus content of sedimentary rocks is less than 0.2%. The phosphate is present as fluorapatite Ca5(PO4)3F typically in cryptocrystalline masses (grain sizes < 1 μm) referred to as collophane-sedimentary apatite deposits of uncertain origin. It is also present as hydroxyapatite Ca5(PO4)3OH or Ca10(PO4)6(OH)2, which is often dissolved from vertebrate bones and teeth, whereas fluorapatite can originate from hydrothermal veins. Other sources also include chemically dissolved phosphate minerals from igneous and metamorphic rocks. Phosphorite deposits often occur in extensive layers, which cumulatively cover tens of thousands of square kilometres of the Earth's crust.
City Island Harbor is the protected body of water between City Island and Hart Island in the Bronx, New York City, open to Long Island Sound at its northern and southern extremities. It is not a true harbor, but a sound. Other minor islands in and around City Island Harbor include the Chimney Sweeps Islands, the Blauzes, and Rat Island. Green Flats Reef is exposed at low tide.
Cuban Ledge is a reef or islet composed chiefly of sand and small rocks in Eastchester Bay, the Bronx, in Long Island Sound. It is located between Rodman's Neck and Country Club in Eastchester Bay and is visible only during periods of low tide. It is a hazard to boats, and is marked with a signal tower.
The Hypocrite Channel is a small channel in Massachusetts Bay, located within the city limits of Boston. It's also located within the Boston Harbor Islands National Recreation Area. The channel runs between the islands of Half Tide Rocks, Calf Island, Little Calf Island, and Green Island.
Mussel Rock is a rock formation on the coast of San Mateo County, California, offshore from Daly City. It consists of one large and numerous smaller rocks of a type known as a stack, where a headland is eroded unevenly, leaving small islands. The rock itself is located 15 meters from the shore of Mussel Rock Park and stands 18 meters tall.
Scott and Seringapatam Reefs is a group of atoll-like reefs in the Timor Sea more than 300 kilometres (190 mi) northwest of Cape Leveque, Western Australia, on the edge of the continental shelf. There are three or four separate reef structures, depending on whether Scott Reef Central is counted separately.
Built for the French Line, Antilles was a near-sister to SS Flandre of 1952. Her construction was completed and her maiden voyage made in 1953. She differed from her sister mainly because she was painted white. She was placed on West Indies cruise service in the 1960s.
The Seven Stones reef is a rocky reef nearly 15 miles (24 km) west-northwest (WNW) of Land's End, Cornwall and 7 miles (11 km) east-northeast (ENE) of the Isles of Scilly. The reef consists of two groups of rocks and is nearly 2 miles (3.2 km) long and 1 mile (1.6 km) in breadth. They rise out of deep water and are a navigational hazard for shipping with 71 named wrecks and an estimated 200 shipwrecks overall. The most infamous is the Torrey Canyon in 1967, which was at that time the world's costliest shipping disaster, and to date, still the worst oil spill on the coast of the United Kingdom.
The Davenport Tide Pools are located just past the town of Davenport, California in the United States. They are located off Davenport Landing, which is a street off Highway 1. The tide pools are unique due to the ridges that run up and down the tide pools, allowing for different organisms to live close, even though in a normal habitat they would be unable to do so. The Beach is open sunrise to sunset, and is day use only.
Cape Town lies at the south-western corner of the continent of Africa. It is bounded to the south and west by the Atlantic Ocean, and to the north and east by various other municipalities in the Western Cape province of South Africa.
The Carr is a sandstone reef on the headland between the Firth of Forth and St Andrews Bay. There have been many ships wrecked on the reef, which lies on the busy shipping lanes into the Forth ports and the River Tay.
Mussel Island was an island in Newtown Creek located near its confluence with Maspeth Creek, between the Brooklyn neighborhood of Greenpoint and the Queens neighborhood of Maspeth in New York City.
Middle Ground is a large submerged reef in Long Island Sound and part of the city of New Rochelle, in Westchester County, New York. This underwater embankment formed from the natural accumulation of rock and sand in shallow coastal waters. Rock outcrops just below the surface at the center of Middle Ground become exposed during low tide. Stripers and Bluefish are attracted to the shoal throughout the warmer season.
The Fox Islands Passes are waterways in the Fox Islands area of the U.S. state of Alaska, connecting the Bering Sea with the North Pacific Ocean.
The removal of obstructive rocks from Hell Gate, a narrow tidal strait in New York City's East River and a major water transportation route, began in 1849, when French engineer Benjamin Maillefert, cleared some of the rocks. Then in 1851, the U.S. Army Corps of Engineers, led by General John Newton, began to do the job, in an operation which was to span 70 years. On September 24, 1876, the Corps used 50,000 pounds (23,000 kg) of explosives to blast the rocks, which was followed by further blasting. The process was started by excavating under Hallets reef from Astoria. Cornish miners, assisted by steam drills, dug galleries under the reef, which were then interconnected. They later drilled holes for explosives. A patent was issued for the detonating device. After the explosion, the rock debris was dredged and dropped into a deep part of the river. This was not repeated at the later Flood Rock explosion.
Baktriana Reef is the 360 m long in east-west direction and 40 m wide flat and rocky low-tide elevation off the west coast of Snow Island in the South Shetland Islands, Antarctica. Its surface area is 0.33 ha. The vicinity was visited by early 19th century sealers.
Ballestilla Reef is the 160 m long in southeast-northwest direction and 40 m wide flat and rocky low-tide elevation off the northwest coast of Snow Island in the South Shetland Islands, Antarctica. Its surface area is 0.38 ha. The vicinity was visited by early 19th century sealers.
