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Blue Hole (Guam)
Blue Hole is a blue hole dive site off the western coast of Guam. It is variously described as "Guam’s signature natural feature dive," "the most requested dive site on Guam," and "one of Guam’s most popular divesites". It is located in northern Agat Bay, just south of the entrance to Apra Harbor. Despite being very close to the southern coast of the Orote Peninsula, sheer cliffs mean that it is done exclusively as a boat dive, typically out of Cabras Marina in Apra Harbor, located 20 minutes away. The top of the underwater sinkhole begins at about and drops to more than . However, the sinkhole is located next to a wall and there is an opening that allows exit at about , putting it just within the limits of an advanced recreational dive, depending on certifying agency. The opening of the sinkhole appears to be a heart shape to divers within it. While entry to the site is done while the dive boat is hooked into a mooring buoy, exit typically requires deploying a surface marke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinkhole
A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are locally also known as ''vrtače'' and shakeholes, and to openings where surface water enters into underground passages known as ''ponor'', swallow hole or swallet. A ''cenote'' is a type of sinkhole that exposes groundwater underneath. A ''sink'' or ''stream sink'' are more general terms for sites that drain surface water, possibly by infiltration into sediment or crumbled rock. Most sinkholes are caused by karst processes – the chemical dissolution of carbonate rocks, collapse or suffosion processes. Sinkholes are usually circular and vary in size from tens to hundreds of meters both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may form gradually or suddenly, and are found worldwide. Formation Natural processes Sinkholes may capture surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guam
Guam (; ch, Guåhan ) is an organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. It is the westernmost point and territory of the United States (reckoned from the geographic center of the U.S.); its capital Hagåtña (144°45'00"E) lies further west than Melbourne, Australia (144°57'47"E). In Oceania, Guam is the largest and southernmost of the Mariana Islands and the largest island in Micronesia. Guam's capital is Hagåtña, and the most populous village is Dededo. People born on Guam are American citizens but have no vote in the United States presidential elections while residing on Guam and Guam delegates to the United States House of Representatives have no vote on the floor. Indigenous Guamanians are the Chamoru, historically known as the Chamorro, who are related to the Austronesian peoples of Indonesia, the Philippines, Malaysia, Taiwan, Micronesia, and Polynesia. As of 2022, Guam's population is 168, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orote Peninsula
The Orote Peninsula is a four kilometer-long peninsula jutting from the west coast of the United States territory of Guam. A major geologic feature of the island, it forms the southern coast of Apra Harbor and the northern coast of Agat Bay. Its tip, Point Udall, is Guam's westernmost point and also the United States' westernmost point by travel, not longitude. The peninsula historically was the site of the important Chamorro village of Sumay, Guam, Sumay, as well as Fort Santiago, Guam, Fort Santiago of the Spanish colonial period. In modern times, the peninsula is politically in the Villages of Guam, village of Santa Rita, Guam, Santa Rita, but it is controlled in its entirety by Naval Base Guam. Geology Orote Peninsula, like the eastern Guam, is a raised limestone plateau reaching heights of 190 ft (58m). The limestone dates to the Pliocene to Pleistocene, known as "Mariana limestone." It thus differs dramatically from areas immediately inland, which are volcanic high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agat Bay
Agat Bay is a bay on the west coast of Guam. Its northern boundary is the Orote Peninsula, occupied entirely by Naval Base Guam, which itself lies within the village of Sånta Rita-Sumai, Guam, Sånta Rita-Sumai. The bay stretches south along the coast of the village of Hågat, Guam, Hågat (formerly, Agat) to Facpi Point. With a length of some seven kilometers, the bay stretches for nearly one fifth of the west coast of Guam. The Asan Invasion Beach of the 1944 Battle of Guam (1944), Battle of Guam is commemorated by the Agat Unit of War in the Pacific National Historical Park, which spans surce and subsurface areas from Apaca Point to Bangi Point. The NRHP-listed Agat World War II Amtrac is submerged off Agat Cemetery. The northern part of the bay is protected by an offshore reef. Blue Hole (Guam), Blue Hole, one of Guam's most popular scuba diving sites, is located in the northwest corner of the bay. Agat Marina in the southern portion of the bay has 100 slips and mainly berths r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-water Diving
In underwater diving, open water is unrestricted water such as a sea, lake or flooded quarries. It is the opposite of confined water (usually a swimming pool) where diver training takes place. Open water also means the diver has direct vertical access to the surface of the water in contact with the Earth's atmosphere.Open water diving implies that if a problem arises, the diver can directly ascend vertically to the atmosphere to breathe air. Penetration diving—involving entering caves or wrecks, or diving under ice—is therefore not "open water diving". In some contexts the lack of a decompression obligation is considered a necessary condition for classification of a dive as an open water dive, but this does not affect the classification of the venue as open water. Swim-throughs – the recreational diving term for arches and short, clear, tunnels where the light can be seen at the far end, are technically an overhead environment, but this is often overlooked by divers as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Diving
Deep diving is underwater diving to a depth beyond the norm accepted by the associated community. In some cases this is a prescribed limit established by an authority, while in others it is associated with a level of certification or training, and it may vary depending on whether the diving is recreational, technical or commercial. Nitrogen narcosis becomes a hazard below and hypoxic breathing gas is required below to lessen the risk of oxygen toxicity. For some recreational diving agencies, "Deep diving", or "Deep diver" may be a certification awarded to divers that have been trained to dive to a specified depth range, generally deeper than . However, the Professional Association of Diving Instructors (PADI) defines anything from as a "deep dive" in the context of recreational diving (other diving organisations vary), and considers ''deep diving'' a form of technical diving. In technical diving, a depth below about where hypoxic breathing gas becomes necessary to avoid oxyge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue Hole
A blue hole is a large marine cavern or sinkhole, which is open to the surface and has developed in a bank or island composed of a carbonate bedrock (limestone or coral reef). Their existence was discovered in the late 20th century by fishermen and recreational divers. Blue holes typically contain tidally influenced water of fresh, marine, or mixed chemistry. They extend below sea level for most of their depth and may provide access to submerged cave passages. Well-known examples are the Dragon Hole (in the South China Sea) and, in the Caribbean, the Great Blue Hole and Dean's Blue Hole. ''Blue holes'' are distinguished from ''cenotes'' in that the latter are inland voids usually containing fresh groundwater rather than seawater. Description Blue holes are roughly circular, steep-walled depressions, and so named for the dramatic contrast between the dark blue, deep waters of their depths and the lighter blue of the shallows around them. Their water circulation is poor, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apra Harbor
Apra Harbor, also called Port Apra, is a deep-water port on the western side of the United States territory of Guam. It is considered one of the best natural ports in the Pacific Ocean. The harbor is bounded by Cabras Island and the Glass Breakwater to the north and the Orote Peninsula in the south. Naval Base Guam and the Port of Guam are the two major users of the harbor. It is also a popular recreation area for boaters, surfers, scuba divers, and other recreationalists. Geography The geography of Apra Harbor has been extensively modified from its pre-historical state by humans. The entrance to the harbor is flanked by Point Udall, formerly Orote Point, to the south and Spanish Rocks at the tip of the Glass Breakwater. The Glass Breakwater, built on top of Calalan Bank and the fringing Luminao Reef, connects to Cabras Island, the location of the Port of Guam, which handles more than 90% of civilian cargo imported to Guam. Inland areas in the villages of Piti and Santa Rita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cabras Marina
{{geodis ...
Cabras may refer to the following places: * Cabras, Sardinia, a town in Italy * Cabras Island, on Guam * Pino Cabras (born 1968), Italian politician * Ilha das Cabras, an island in the municipality of Ilhabela, São Paulo, Brazil * Ilhéu das Cabras, an island of São Tomé and Príncipe * Cabras Islets, Island in the Azores, Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delayed Surface Marker Buoy
A surface marker buoy, SMB, dive float or simply a blob is a buoy used by scuba divers, at the end of a line from the diver, intended to indicate the diver's position to people at the surface while the diver is underwater. Two kinds are used; one (SMB) is towed for the whole dive, and indicates the position of the dive group throughout the dive, and the other, a delayed surface marker buoy, DSMB or decompression buoy, is deployed towards the end of the dive as a signal to the surface that the divers have started to ascend, and where they are going to surface. Both types can also function as a depth reference for controlling speed of ascent and accurately maintaining depth at decompression stops. Surface marker buoys are also used by freedivers in open water, to indicate the approximate position of the diver when submerged. They may also be used to support a catch bag or fish stringer by underwater hunters and collectors. A DSMB is considered by recreational scuba divers and ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelagic Fish
Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that do live on or near the bottom, and reef fish that are associated with coral reefs. The marine pelagic environment is the largest aquatic habitat on Earth, occupying 1,370 million cubic kilometres (330 million cubic miles), and is the habitat for 11% of known fish species. The oceans have a mean depth of . About 98% of the total water volume is below , and 75% is below . Moyle and Cech, p. 585 Marine pelagic fish can be divided into coastal (inshore) fish and oceanic (offshore) fish. Coastal pelagic fish inhabit the relatively shallow and sunlit waters above the continental shelf, while oceanic pelagic fish inhabit the vast and deep waters beyond the continental shelf (even though they also may swim inshore). Pelagic fish range in size from small coastal forage fish, such as herrings and sardines, to large apex pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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