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47-foot Motor Lifeboat
The 47-foot MLB is the standard lifeboat of the United States Coast Guard (USCG). The 47′ MLB is the successor to the 44′ MLB. At Station Chatham where the new 47-foot boat would draw too much to get over the bar, the 42-foot Near Shore Lifeboat was designed to replace the 44' MLB. The 47′ MLB is designed to weather hurricane force winds and heavy seas, capable of surviving winds up to , breaking surf up to and impacts up to three G's. If the boat should capsize, it self-rights in less than ten seconds with all equipment fully functional. The boat's hull and superstructure are constructed entirely from 5456 marine grade aluminum. Designed with a hard chined deep "V" planing hull, the 47′ MLB exceeds its hull speed. The frame is composed of 17 vertical bulkhead frames, each of which is welded to the deck and hull, and five of which are watertight. Employing "fly-by-wire" control systems, the boat can be operated from four different locations: two from the enclosed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surf Zone
As ocean surface waves approach shore, they get taller and break, forming the foamy, bubbly surface called ''surf''. The region of breaking waves defines the surf zone, or breaker zone. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the beach, forming an uprush of water called swash. The water then runs back again as backwash. The nearshore zone where wave water comes onto the beach is the surf zone. The water in the surf zone is shallow, usually between deep; this causes the waves to be unstable. Animal life The animals that often are found living in the surf zone are crabs, clams, and snails. Surf clams and mole crabs are two species that stand out as inhabitants of the surf zone. Both of these animals are very fast burrowers. The surf clam, also known as the variable coquina, is a filter feeder that uses its gills to filter microalgae, tiny zooplankton, and small particulates out of seawater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chine (boating)
A chine in boat design is a sharp change in angle in the Cross_section_(geometry), cross section of a hull (watercraft), hull. The chine typically arises from the use of sheet materials (such as sheet metal or marine ply) as the mode of construction. Rationale of chines Using sheet materials in boat construction is cheap and simple, but whereas these sheet materials are flexible longitudinally, they tend to be rigid vertically. Examples of steel vessels with hard chines include narrowboats and widebeams; examples of plywood vessels with hard chines include sailing dinghies such as the single-chined Graduate (dinghy), Graduate and the double-chined Enterprise (dinghy), Enterprise. Although a hull made from sheet materials might be unattractively "slab-sided", most chined hulls are designed to be pleasing to the eye and hydrodynamics, hydrodynamically efficient. Hulls without chines (such as Clinker (boat building), clinker-built or Carvel (boat building), carvel-built vessels) u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trent-class Lifeboat
The Trent-class lifeboat is an all-weather lifeboat operated by the Royal National Lifeboat Institution (RNLI) from 30 stations around the coasts of Great Britain and Ireland to provide coverage up to out to sea. Introduced to service in 1994, the class is named after the River Trent, the second longest river wholly in England. History In the 1980s the RNLI's and all-weather lifeboats provided coverage out to sea, operating at up to to cover the distance in two hours in good weather. However the RNLI felt that they needed the capability to extend their coverage to radius which would require lifeboats with a top speed of . This resulted in the Trent and lifeboats. The prototype for the Trent class was built in 1991. It was used for trials until 1994, when it was put into active service at Alderney Lifeboat Station. It remained on station there until their own boat was available in 1995, since when it has served in the relief fleet. Construction of its sister boats contin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Response Boat – Medium
The Response Boat – Medium (RB-M) is a utility boat used by the United States Coast Guard. It is a replacement for the Coast Guard's retired fleet of utility boats (UTB), which had been in use by the Coast Guard since the 1970s. On June 21, 2006 the USCG awarded the RB-M contract to Marinette Marine of Marinette, Wisconsin and Kvichak Marine Industries of Seattle, Washington. The RB-M was designed by Camarc Design in the UK. Between June of 2006 and March of 2015 Marinette, in Green Bay Wisconsin and Kvichak in Kent, Washington partnered to build and deliver 174 RB-Ms to the USCG. Kvichak developed and delivered several police boat variants to several cities including Seattle and New York. In the summer of 2017, the Canadian Coast Guard purchased a used 45 RBM from the United States Coast Guard. It is based in Vancouver British Columbia under the name CCGS ''Laredo Sound''. According to the US Coast Guard, "While primarily a search and rescue asset when the 41' UTB was fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Coast Guard
The Canadian Coast Guard (CCG; french: links=no, Garde côtière canadienne, GCC) is the coast guard of Canada. Formed in 1962, the coast guard is tasked with marine search and rescue (SAR), communication, navigation, and transportation issues in Canadian waters, such as navigation aids and icebreaking, marine pollution response, and support for other Canadian government initiatives. The coast guard operates 119 vessels of varying sizes and 23 helicopters, along with a variety of smaller craft. The CCG is headquartered in Ottawa, Ontario, and is a special operating agency within Fisheries and Oceans Canada (Department of Fisheries and Oceans). Role and responsibility Unlike armed coast guards of some other nations, the CCG is a government marine organization without naval or law enforcement responsibilities. Naval operations in Canada's maritime environment are exclusively the responsibility of the Royal Canadian Navy. Enforcement of Canada's maritime-related federal statutes ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape-class Motor Lifeboat
The Canadian Coast Guard (CCG) maintains a fleet of Cape-class motor lifeboats based on a motor lifeboat design used by the United States Coast Guard. In September 2009 the CCG announced plans to add five new lifeboats, bringing the total number of Cape-class lifeboats to 36. The vessels are staffed by a crew of four, two of whom are rescue specialists. In spite of its name, the CCGS ''Cape Roger'' is a larger patrol vessel, not a Cape-class lifeboat. The CCG also maintains some larger motor lifeboats based on Arun-class lifeboats designed in the United Kingdom. In 2021 a contract was awarded to Ocean Pacific Marine to upgrade the class over a 7 year period. Design Cape-class motor lifeboats have displacements of , total lengths of and beams of . Constructed from marine-grade aluminium, ships have draughts of . They contain two Caterpillar 3196 diesel engines providing a combined . They have two four-blade propellers, and each ship's complement is four crew members ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
41-foot Utility Boat, Large
The USCG Utility Boat, or UTB, was a standard utility boat used by the United States Coast Guard for a variety of inshore and offshore missions. General information The 41 ft (12 m) UTB was designed to operate under moderate weather and sea conditions where its speed and maneuverability made it an ideal platform; however, due to the modified "V" design when the 41ft UTB when operated in a following seaway it had a tendency to be pushed to the starboard or port making it difficult when entering an entrance. Overall, the 41ft UTB was a vast improvement over the previous 40ft UTB's as the previous UTB's offered little to no protection from the sun, sea and wind conditions for the crew. The boats were welded 5086 aluminum, with a molded fiberglass superstructure and twin Cummins diesel engines with conventional shafts and propellers. They were capable of light towing, and were originally fitted with demountable fire monitors. Typical boat crew was three. 207 boats were constru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hull Speed
Hull speed or displacement speed is the speed at which the wavelength of a vessel's bow wave is equal to the waterline length of the vessel. As boat speed increases from rest, the wavelength of the bow wave increases, and usually its crest-to-trough dimension (height) increases as well. When hull speed is exceeded, a vessel in displacement mode will appear to be climbing up the back of its bow wave. From a technical perspective, at hull speed the bow and stern waves interfere constructively, creating relatively large waves, and thus a relatively large value of wave drag. Ship drag for a displacement hull increases smoothly with speed as hull speed is approached and exceeded, often with no noticeable inflection at hull speed. The concept of hull speed is not used in modern naval architecture, where considerations of speed/length ratio or Froude number are considered more helpful. Background As a ship moves in the water, it creates standing waves that oppose its movement. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planing (sailing)
Planing ( ) is the mode of operation for a waterborne craft in which its weight is predominantly supported by hydrodynamic lift, rather than hydrostatic lift (buoyancy). Many forms of marine transport make use of planing, including fast ferries, racing boats, floatplanes, flying boats, seaplanes, and water skis. Most surfboards are planing or semi-planing hulls. Beyond planing, fast vessel designs have seen a transition to hydrofoil designs. History The earliest documented planing sailboat was a proa built in 1898 by Commodore Ralph Munroe. It was capable of speeds of more than twice the hull speed. Planing a sailing dinghy was first popularised by Uffa Fox in Britain. In 1928 Fox introduced planing to the racing world in his International 14 dinghy, ''Avenger''. That year he gained 52 first places, 2 seconds, and 3 third places out of 57 race starts. This performance was noticed by other designers who further developed them. Over the years many dinghies have acquired the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hull (watercraft)
A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top (such as a dinghy), or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast. The line where the hull meets the water surface is called the waterline. General features There is a wide variety of hull types that are chosen for suitability for different usages, the hull shape being dependent upon the needs of the design. Shapes range from a nearly perfect box in the case of scow barges to a needle-sharp surface of revolution in the case of a racing multihull sailboat. The shape is chosen to strike a balance between cost, hydrostatic considerations (accommodation, load carrying, and stability), hydrodynamics (speed, power requirements, and motion and behavior in a seaway) and special considerations for the ship's role, such as the rounded bow of an icebreaker or the flat bottom of a landing craft. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morro Bay, California
Morro Bay (''Morro'', Spanish language, Spanish for "Hill") is a seaside city in San Luis Obispo County, California. Located on the Central Coast (California), Central Coast of California, the city population was 10,757 as of the 2020 United States Census, 2020 census, up from 10,234 at the 2010 United States Census, 2010 census. The town overlooks Morro Bay, a natural embayment with an all-weather small craft commercial and recreational harbor. History The prehistory of Morro Bay relates to Chumash people, Chumash settlement, particularly near the mouth of Morro Creek. At least as early as the Millingstone Horizon thousands of years before present, there was an extensive settlement along the banks and terraces above Morro Creek. A tribal site on present-day Morro Bay was named ''tsɨtqawɨ'', Obispeño language, Obispeño for "Place of the Dogs". The first European land exploration of Alta California, the Spanish Portolá expedition, came down Los Osos Valley and camped near ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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