网页Sea area A1 is that sea area which is within a circle of radius A nautical miles over which the radio propagation path lies substantially over water. The radius A is equal to the transmission distance between a ship's VHF antenna at a height of 4 m above sea level and the antenna of the VHF coast station which lies at the centre of the circle.
Maritime Zones and Boundaries | National Oceanic and …
网页2024年4月16日 · The Area is comprised of the seabed and subsoil beyond the limits of national jurisdiction. It does not include superjacent waters (i.e., the water column) or the air space above those waters. The Area and its resources are the common heritage of mankind, and no State may claim or exercise sovereignty or sovereign rights over any part of the ...
List of seas on Earth - Wikipedia
网页This is a list of seas of the World Ocean, including marginal seas, areas of water, various gulfs, bights, bays, and straits. [ 2 ] In many cases it is a matter of tradition for a body of water to be named a sea or a bay, etc., therefore all these types are listed here.
Ocean - Wikipedia
网页The following names describe five different areas of the ocean: Pacific, Atlantic, Indian, Antarctic/Southern, and Arctic. [10][11] The ocean contains 97% of Earth's water [8] and is the primary component of Earth's hydrosphere; thus the ocean is essential to life on Earth.
Sea - Wikipedia
网页A sea is a large body of salty water. There are particular seas and the sea. The sea commonly refers to the World Ocean, the wider body of seawater. Particular seas are either marginal seas, second-order sections of the oceanic sea (e.g. the Mediterranean Sea), or certain large, nearly landlocked bodies of water.
GMDSS Areas and Search and Rescue Areas | Navigation Center
网页The Coast Guard defines Sea Area A1 as those areas where more than ninety percent of the area within 20 nautical miles seaward of the territorial baseline along the East, West and Gulf Coasts of the United States, excluding Alaska, and including Hawaii, Puerto Rico, Guam, the Virgin Islands of the United States and the Northern Mariana Islands ...
What are Sea Areas as per GMDSS - MarineGyaan
网页GMDSS divides the world’s oceans into four “sea areas”, designated A1 through A4. An area within the radiotelephone coverage of at least one VHF coast station in continuous digital selective calling (DSC), alerting is available. Area could extend up to 30-50 Nautical Miles.
Particularly Sensitive Sea Areas - IMO
网页A Particularly Sensitive Sea Area (PSSA) is an area that needs special protection through action by IMO because of its significance for recognized ecological or socio-economic or scientific reasons and which may be vulnerable to damage by …
World Ocean Database | National Centers for Environmental Information ...
网页The World Ocean Database (WOD) is world's largest collection of uniformly formatted, quality controlled, publicly available ocean profile data.
Sea - National Geographic Society
网页2023年10月19日 · A sea can be more than 2.6 million square kilometers (1 million square miles) in area, such as the Caribbean Sea. Or, it can be as tiny as the Sea of Marmara, which is less than 12,950 square kilometers (5,000 square miles) in area.