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107-482: The chief mate answers to the captain for the safety and security of the ship. Responsibilities include the crew's welfare and training in areas such as safety, firefighting, search and rescue. The Chief Mate, who is the second in command of the vessel, is often equated, in corporate terms, to a senior manager for the operations on board, as the Mate is in charge of a number of departmental functions. In modern cargo vessels,

214-461: A binnacle . This preserves the horizontal position. The magnetic compass is very reliable at moderate latitudes, but in geographic regions near the Earth's magnetic poles it becomes unusable. As the compass is moved closer to one of the magnetic poles, the magnetic declination, the difference between the direction to geographical north and magnetic north, becomes greater and greater. At some point close to

321-470: A jewel bearing , so it can turn easily. When the compass is held level, the needle turns until, after a few seconds to allow oscillations to die out, it settles into its equilibrium orientation. In navigation, directions on maps are usually expressed with reference to geographical or true north , the direction toward the Geographical North Pole , the rotation axis of the Earth. Depending on where

428-477: A multi-lingual crew. At sea, the mate on watch has three fundamental duties: navigate the ship, safely avoid traffic, and respond to any emergencies that may arise. Mates generally stand watch with able seamen who act as helmsman and lookout . The helmsman executes turns and the lookout reports dangers such as approaching ships. These roles are often combined to a single helmsman/lookout and, under some circumstances, are eliminated. The ability to smartly handle

535-489: A purser , the captain is in charge of the ship's accounting . This includes ensuring an adequate amount of cash on board, coordinating the ship's payroll (including draws and advances), and managing the ship's slop chest . On international voyages, the captain is responsible for satisfying requirements of the local immigration and customs officials. Immigration issues can include situations such as embarking and disembarking passengers, handling crew members who desert

642-907: A "considerable increase" in the job market over the next few years. As of 2013, captains of U.S.-flagged deep sea vessels make up to US$ 1,500 per day, or US$ 80,000 to US$ 300,000 per year. Captains of smaller vessels in the inland and coastal trade earn between US$ 350 and US$ 700 per day, or US$ 65,000 to $ 180,000 per year. Captains of large ferries average US$ 56,794 annually. In 2005, 3,393 mariners held active unlimited master's licenses. 87 held near-coastal licenses with unlimited tonnage, 291 held unlimited tonnage master's licenses on inland and Great Lakes waters, while 1,044 held unlimited licenses upon inland waters only. Some 47,163 active masters licenses that year had tonnage restrictions, well over half of those being for near-coastal vessels of up to 100 tons gross tonnage . As of 2006, some 34,000 people were employed as captains, mates, and pilots of water vessels in

749-444: A Third Mate's license. A master of 1,600 ton vessels can, under certain circumstances, begin the application process for an unlimited third mate's license. If approved the applicant must then successfully pass a comprehensive license examination before being issued the license. Hawsepiper is an informal maritime industry term used to refer to an officer who began his or her career as an unlicensed merchant seaman and did not attend

856-518: A bowl of water it becomes a compass. Such devices were universally used as compasses until the invention of the box-like compass with a "dry" pivoting needle, sometime around 1300. Originally, many compasses were marked only as to the direction of magnetic north, or to the four cardinal points (north, south, east, west). Later, these were divided, in China into 24, and in Europe into 32 equally spaced points around

963-405: A compass card, which moves freely on a pivot. A lubber line , which can be a marking on the compass bowl or a small fixed needle, indicates the ship's heading on the compass card. Traditionally the card is divided into thirty-two points (known as rhumbs ), although modern compasses are marked in degrees rather than cardinal points. The glass-covered box (or bowl) contains a suspended gimbal within

1070-413: A compass, for example, certain rocks which contain magnetic minerals, like Magnetite . This is often indicated by a rock with a surface which is dark and has a metallic luster, not all magnetic mineral bearing rocks have this indication. To see if a rock or an area is causing interference on a compass, get out of the area, and see if the needle on the compass moves. If it does, it means that the area or rock

1177-462: A cornerstone of safe watchkeeping. Safety requires that one live these rules and follows the principles of safe watchkeeping. Maximizing bridge teamwork, including the practice of Bridge Resource Management , is an emerging focus in watchkeeping. The main purpose for Radar and Automatic Radar Plotting Aids (ARPA) on a ship's bridge is to move safely among other vessels. These instruments help to accurately judge information about prominent objects in

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1284-631: A device for divination as early as the Chinese Han dynasty (since c. 206 BC), and later adopted for navigation by the Song dynasty Chinese during the 11th century. The first usage of a compass recorded in Western Europe and the Islamic world occurred around 1190. The magnetic compass is the most familiar compass type. It functions as a pointer to " magnetic north ", the local magnetic meridian, because

1391-457: A different method. To take a map bearing or true bearing (a bearing taken in reference to true, not magnetic north) to a destination with a protractor compass , the edge of the compass is placed on the map so that it connects the current location with the desired destination (some sources recommend physically drawing a line). The orienting lines in the base of the compass dial are then rotated to align with actual or true north by aligning them with

1498-459: A few countries, such as UK, USA and Italy, some captains with particular experience in navigation and command at sea , may be named commodore or senior captain or captain senior grade . The term master is descended from the Latin magister navis , used during the imperial Roman age to designate the nobleman ( patrician ) who was in ultimate authority on board a vessel. The magister navis had

1605-488: A few nations, notably the United States Army, continue to issue field compasses with magnetized compass dials or cards instead of needles. A magnetic card compass is usually equipped with an optical, lensatic, or prismatic sight , which allows the user to read the bearing or azimuth off the compass card while simultaneously aligning the compass with the objective (see photo). Magnetic card compass designs normally require

1712-437: A fixed point while its heading is noted by alignment with fixed points on the shore. A compass deviation card is prepared so that the navigator can convert between compass and magnetic headings. The compass can be corrected in three ways. First the lubber line can be adjusted so that it is aligned with the direction in which the ship travels, then the effects of permanent magnets can be corrected for by small magnets fitted within

1819-399: A flexible rubber diaphragm or airspace inside the capsule to allow for volume changes caused by temperature or altitude, some modern liquid compasses use smaller housings and/or flexible capsule materials to accomplish the same result. The liquid inside the capsule serves to damp the movement of the needle, reducing oscillation time and increasing stability. Key points on the compass, including

1926-409: A general responsibility for the ship's stability and special care for cargoes that are dangerous, hazardous or harmful. Even under the best of conditions, a ship is balanced precariously upon the water and is subject to a number of forces, such as wind, swells, and storms, which could capsize it. The cargo officer uses tools like ballasting and load balancing to optimize the ship's performance for

2033-443: A liaison to local investigators and is responsible for providing complete and accurate logbooks, reports, statements and evidence to document an incident. Specific examples of the ship causing external damage include collisions with other ships or with fixed objects, grounding the vessel, and dragging anchor. Some common causes of cargo damage include heavy weather, water damage, pilferage, and damage caused during loading/unloading by

2140-573: A lodestone, which appeared in China by 1088 during the Song dynasty , as described by Shen Kuo . Dry compasses began to appear around 1300 in Medieval Europe and the Islamic world . This was supplanted in the early 20th century by the liquid-filled magnetic compass. Modern compasses usually use a magnetized needle or dial inside a capsule completely filled with a liquid (lamp oil, mineral oil, white spirits, purified kerosene, or ethyl alcohol are common). While older designs commonly incorporated

2247-405: A low-friction surface to allow it to freely pivot to align itself with the magnetic field. It is then labeled so the user can distinguish the north-pointing from the south-pointing end; in modern convention the north end is typically marked in some way. If a needle is rubbed on a lodestone or other magnet, the needle becomes magnetized. When it is inserted in a cork or piece of wood, and placed in

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2354-455: A map with the latest declination information should be used. Some magnetic compasses include means to manually compensate for the magnetic declination, so that the compass shows true directions. The first compasses in ancient Han dynasty China were made of lodestone , a naturally magnetized ore of iron. The wet compass reached Southern India in the 4th century AD. Later compasses were made of iron needles, magnetized by striking them with

2461-627: A map. Other features found on modern orienteering compasses are map and romer scales for measuring distances and plotting positions on maps, luminous markings on the face or bezels, various sighting mechanisms (mirror, prism, etc.) for taking bearings of distant objects with greater precision, gimbal-mounted, "global" needles for use in differing hemispheres, special rare-earth magnets to stabilize compass needles, adjustable declination for obtaining instant true bearings without resorting to arithmetic, and devices such as inclinometers for measuring gradients. The sport of orienteering has also resulted in

2568-434: A marked line of longitude (or the vertical margin of the map), ignoring the compass needle entirely. The resulting true bearing or map bearing may then be read at the degree indicator or direction-of-travel (DOT) line, which may be followed as an azimuth (course) to the destination. If a magnetic north bearing or compass bearing is desired, the compass must be adjusted by the amount of magnetic declination before using

2675-456: A marriage ceremony on board his ship or aircraft. He shall not permit a marriage ceremony to be performed on board when the ship or aircraft is outside the territory of the United States." However, there may be exceptions "in accordance with local laws and the laws of the state, territory, or district in which the parties are domiciled" and "in the presence of a diplomatic or consular official of

2782-406: A merchant vessel. The captain is responsible for the safe and efficient operation of the ship, including its seaworthiness, safety and security, cargo operations, navigation, crew management, and legal compliance, and for the persons and cargo on board. The captain ensures that the ship complies with local and international laws and complies also with company and flag state policies. The captain

2889-533: A microprocessor. Often, the device is a discrete component which outputs either a digital or analog signal proportional to its orientation. This signal is interpreted by a controller or microprocessor and either used internally, or sent to a display unit. The sensor uses highly calibrated internal electronics to measure the response of the device to the Earth's magnetic field. Apart from navigational compasses, other specialty compasses have also been designed to accommodate specific uses. These include: A magnetic rod

2996-419: A needle lock is fitted to the compass to reduce wear, operated by the folding action of the rear sight/lens holder. The use of air-filled induction compasses has declined over the years, as they may become inoperative or inaccurate in freezing temperatures or extremely humid environments due to condensation or water ingress. Some military compasses, like the U.S. M-1950 ( Cammenga 3H) military lensatic compass,

3103-403: A separate magnetized needle inside a rotating capsule, an orienting "box" or gate for aligning the needle with magnetic north, a transparent base containing map orienting lines, and a bezel (outer dial) marked in degrees or other units of angular measurement. The capsule is mounted in a transparent baseplate containing a direction-of-travel (DOT) indicator for use in taking bearings directly from

3210-469: A separate protractor tool in order to take bearings directly from a map. The U.S. M-1950 military lensatic compass does not use a liquid-filled capsule as a damping mechanism, but rather electromagnetic induction to control oscillation of its magnetized card. A "deep-well" design is used to allow the compass to be used globally with a card tilt of up to 8 degrees without impairing accuracy. As induction forces provide less damping than fluid-filled designs,

3317-511: A series of training classes and examinations. Training institutions that can lead to a third mate's license include the U.S. Merchant Marine Academy (deck curriculum), the U.S. Coast Guard Academy and U.S. Naval Academy with qualification as an underway officer in charge of a navigational watch , any of the state maritime colleges, the Great Lakes Maritime Academy , or a three-year apprentice mate training program approved by

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3424-441: A ship is key to safe watchstanding. A ship's draught , trim, speed and under-keel clearance all affect its turning radius and stopping distance. Other factors include the effects of wind and current, squat, shallow water and similar effects. Shiphandling is key when the need arises to rescue a man overboard , to anchor, or to moor the ship. The officer must also be able to transmit and receive signals by Morse light and to use

3531-753: A small sliding counterweight installed on the needle. This sliding counterweight, called a "rider", can be used for counterbalancing the needle against the dip caused by inclination if the compass is taken to a zone with a higher or lower dip. Like any magnetic device, compasses are affected by nearby ferrous materials, as well as by strong local electromagnetic forces. Compasses used for wilderness land navigation should not be used in proximity to ferrous metal objects or electromagnetic fields (car electrical systems, automobile engines, steel pitons , etc.) as that can affect their accuracy. Compasses are particularly difficult to use accurately in or near trucks, cars or other mechanized vehicles even when corrected for deviation by

3638-587: A state or the United States Coast Guard . If the vessel carries over six paying passengers, it must be an "inspected vessel" and a higher class license must be obtained by the skipper/master depending on the vessel's gross tons. In the Royal Navy , Royal Marines , U.S. Navy , U.S. Marine Corps , U.S. Coast Guard , and merchant naval slang, it is a term used in reference to the commanding officer of any ship, base, or other command regardless of rank. It

3745-512: A third mate for 365 days to have become a second mate. There are many special cases in license upgrades at the individual level, as licensing regulations change from time to time. A sizable portion of mates still working received their licenses before current laws went into effect. There are two methods to attain an unlimited third mate's license in the United States: to attend a specialized training institution, or to accumulate "sea time" and take

3852-411: A traditional maritime college/academy to earn the officer license. A ship's hawsepipe is the pipe passing through the bow section of a ship that the anchor chain passes through. Hawsepiper refers to climbing up the hawsepipe, a nautical metaphor for climbing up the ship's rank structure. Hawsepiper is considered a positive term when said respectfully. Many hawsepipers are proud of their background and use

3959-463: Is 100 grads to give a circle of 400 grads. Dividing grads into tenths to give a circle of 4000 decigrades has also been used in armies. Most military forces have adopted the French " millieme " system. This is an approximation of a milli-radian (6283 per circle), in which the compass dial is spaced into 6400 units or "mils" for additional precision when measuring angles, laying artillery, etc. The value to

4066-415: Is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose , which can pivot to align itself with magnetic north . Other methods may be used, including gyroscopes, magnetometers , and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and

4173-646: Is a wedding on a ship in port, under the authority of an official from that port. In works of fiction, ship captains have performed marriages in various media, including the 1951 film The African Queen , and episodes of The Love Boat , How I Met Your Mother , The Office and various Star Trek series. Master Mariner certification is regulated internationally under the STCW Convention , specifically Regulation II/2 sets out requirements for Master Mariners. Master mariners can possess either an unlimited certification/licence or one restricted based on tonnage of

4280-477: Is also a constant concern. Knowing the classes and chemistry of fire, fire-fighting appliances, and systems prepares the officer to act fast in case of fire. An officer must be expert in the use of survival craft and rescue boats . Expertise includes the vessels' launching appliances and arrangements, and their equipment including radio life-saving appliances, satellite EPIRBs , SARTs , immersion suits and thermal protective aids. It's important to be expert in

4387-410: Is also more frequently used than captain with privately owned noncommercial or semi-commercial vessels, such as small yachts and other recreational boats, mostly in cases where the person in command of the boat may not be a licensed or professional captain, suggesting the term is less formal. In the U.S., a "skipper" who is in command of a charter vessel that carries paying passengers must be licensed by

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4494-412: Is carrying an electric current. Magnetic compasses are prone to errors in the neighborhood of such bodies. Some compasses include magnets which can be adjusted to compensate for external magnetic fields, making the compass more reliable and accurate. A compass is also subject to errors when the compass is accelerated or decelerated in an airplane or automobile. Depending on which of the Earth's hemispheres

4601-408: Is defined as the angle between the direction of true (geographic) north and the direction of the meridian between the magnetic poles. Variation values for most of the oceans had been calculated and published by 1914. Deviation refers to the response of the compass to local magnetic fields caused by the presence of iron and electric currents; one can partly compensate for these by careful location of

4708-420: Is enough to protect from walking in a substantially different direction than expected over short distances, provided the terrain is fairly flat and visibility is not impaired. By carefully recording distances (time or paces) and magnetic bearings traveled, one can plot a course and return to one's starting point using the compass alone. Compass navigation in conjunction with a map ( terrain association ) requires

4815-569: Is generally only applied to someone who has earned the speaker's respect, and only used with the permission of the commander/commanding officer in question. Skipper RNR was an actual rank used in the British Royal Naval Reserve for skippers of fishing boats who were members of the service. It was equivalent to Warrant Officer . Skippers could also be promoted to Chief Skipper RNR (equivalent to Commissioned Warrant Officer ) and Skipper Lieutenant RNR. Compass A compass

4922-610: Is in charge of the firefighting and damage control teams. He is scene leader and reports via radio to the Captain who is in command and coordinates the larger response from the bridge. The officer must understand distress signals and know the IMO Merchant Ship Search and Rescue Manual. Understanding ship's stability, trim, stress, and the basics of ship's construction is a key to keeping a ship seaworthy. The mate must know what to do in cases of flooding and loss of buoyancy. Fire

5029-404: Is required when constructing a compass. This can be created by aligning an iron or steel rod with Earth's magnetic field and then tempering or striking it. However, this method produces only a weak magnet so other methods are preferred. For example, a magnetised rod can be created by repeatedly rubbing an iron rod with a magnetic lodestone . This magnetised rod (or magnetic needle) is then placed on

5136-732: Is similar to a gyroscope . It is a non-magnetic compass that finds true north by using an (electrically powered) fast-spinning wheel and friction forces in order to exploit the rotation of the Earth. Gyrocompasses are widely used on ships . They have two main advantages over magnetic compasses: Large ships typically rely on a gyrocompass, using the magnetic compass only as a backup. Increasingly, electronic fluxgate compasses are used on smaller vessels. However, magnetic compasses are still widely in use as they can be small, use simple reliable technology, are comparatively cheap, are often easier to use than GPS , require no energy supply, and unlike GPS, are not affected by objects, e.g. trees, that can block

5243-699: Is the UK Honourable Company of Master Mariners . The international parent and representative body is the International Federation of Shipmasters' Associations which has consultative status at the International Maritime Organization . As of 2008, the U.K. Learning and Skills Council lists annual salaries for senior deck officers as ranging from £22,000 to over £50,000 per year. The Council characterizes job opportunities for senior deck officers as "generally good" and expects

5350-454: Is the magnetic bearing to the target. Again, if one is using "true" or map bearings, and the compass does not have preset, pre-adjusted declination, one must additionally add or subtract magnetic declination to convert the magnetic bearing into a true bearing . The exact value of the magnetic declination is place-dependent and varies over time, though declination is frequently given on the map itself or obtainable on-line from various sites. If

5457-427: Is ultimately responsible, under the law, for aspects of operation such as the safe navigation of the ship, its cleanliness and seaworthiness, safe handling of all cargo, management of all personnel, inventory of ship's cash and stores, and maintaining the ship's certificates and documentation. One of a shipmaster's particularly important duties is to ensure compliance with the vessel's security plan, as required by

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5564-421: Is useful for those unfamiliar with the vessel to be able to identify members of the crew and their function. Some companies and some countries use an executive curl similar to that of the Royal Navy . In the United States, and in numerous other maritime countries, captains and officers of shipping companies may wear a merchant navy or merchant marine regular uniform in conjunction with their employment. In

5671-774: The Bahamas permit captains of ships registered in their jurisdictions to perform marriages at sea. Princess Cruises , whose ships are registered in Bermuda, has used this as a selling point for their cruises, while Cunard moved the registration of its ships Queen Mary 2 , Queen Victoria and Queen Elizabeth from Southampton to Bermuda in 2011 to allow marriages to be conducted on their ships. Some captains obtain other credentials (such as ordination as ministers of religion or accreditation as notaries public), which allow them to perform marriages in some jurisdictions where they would otherwise not be permitted to do so. Another possibility

5778-544: The International Code of Signals . Celestial , terrestrial , electronic , and coastal navigation techniques are used to fix a ship's position on a navigational chart . The officer directs the helmsman to keep to track, accounting for effects of winds, tides , currents and estimated speed. The officer uses supplemental information from nautical publications , such as Sailing Directions , tide tables , Notices to Mariners , and radio navigational warnings to keep

5885-422: The International Maritime Organization 's ISPS Code . The plan, customized to meet the needs of each individual ship, spells out duties including conducting searches and inspections, maintaining restricted spaces, and responding to threats from terrorists, hijackers, pirates, and stowaways. The security plan also covers topics such as refugees and asylum seekers , smuggling, and saboteurs. On ships without

5992-473: The Northern Hemisphere , to zone 5 covering Australia and the southern oceans. This individual zone balancing prevents excessive dipping of one end of the needle, which can cause the compass card to stick and give false readings. Some compasses feature a special needle balancing system that will accurately indicate magnetic north regardless of the particular magnetic zone. Other magnetic compasses have

6099-505: The Silva 4b Militaire , and the Suunto M-5N(T) contain the radioactive material tritium ( 1 H ) and a combination of phosphors. The U.S. M-1950 equipped with self-luminous lighting contains 120 mCi (millicuries) of tritium. The purpose of the tritium and phosphors is to provide illumination for the compass, via radioluminescent tritium illumination , which does not require

6206-502: The magnetized needle at its heart aligns itself with the horizontal component of the Earth's magnetic field . The magnetic field exerts a torque on the needle, pulling the North end or pole of the needle approximately toward the Earth's North magnetic pole , and pulling the other toward the Earth's South magnetic pole . The needle is mounted on a low-friction pivot point, in better compasses

6313-528: The stevedores . All persons on board including public authorities, crew, and passengers are under the captain's authority and are his or her ultimate responsibility, particularly during navigation. In the case of injury or death of a crew member or passenger, the master is responsible to address any medical issues affecting the passengers and crew by providing medical care as possible, cooperating with onshore medical personnel, and, if necessary, evacuating those who need more assistance than can be provided on board

6420-468: The Commandant of the U.S. Coast Guard. A seaman may start the process of attaining a license after three years of service in the deck department on ocean steam or motor vessels, at least six months of which as able seaman , boatswain , or quartermaster . Then the seaman takes required training courses, and completes on-board assessments. Finally, the mariner can apply to the United States Coast Guard for

6527-413: The Mate holds appointments like Head of Deck Department, Head of Cargo/Stowage Operations, Head of Safety/Fire Fighting, Head of On-Board Security (Ship Security Officer), Head of Environment and Quality, and so forth. As cargo officer, a chief mate oversees the loading, stowage, securing and unloading of cargoes. Moreover, the chief mate is accountable for the care of cargo during the voyage. This includes

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6634-630: The United States, who has consented to issue the certificates and make the returns required by the consular regulations." Furthermore, in the United States , there have been a few contradictory legal precedents: courts did not recognize a shipboard marriage in California 's 1898 Norman v. Norman but did in New York 's 1929 Fisher v. Fisher (notwithstanding the absence of municipal laws so carried) and in 1933's Johnson v. Baker , an Oregon court ordered

6741-415: The United States. The U.S. Bureau of Labor Statistics projects 18% growth in this occupation, expecting demand for 40,000 shipmasters in 2016. Uniforms are worn aboard many ships, or aboard any vessels of traditional and organized navigation companies, and are required by company regulation on passenger and cruise vessels. In the passenger-carrying trade a unified corporate image is often desired and it

6848-467: The angles increase clockwise , so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearings which are commonly stated in degrees. If local variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north. Among the Four Great Inventions , the magnetic compass was first invented as

6955-456: The baseplate. To check one's progress along a course or azimuth, or to ensure that the object in view is indeed the destination, a new compass reading may be taken to the target if visible (here, the large mountain). After pointing the DOT arrow on the baseplate at the target, the compass is oriented so that the needle is superimposed over the orienting arrow in the capsule. The resulting bearing indicated

7062-489: The bearing so that both map and compass are in agreement. In the given example, the large mountain in the second photo was selected as the target destination on the map. Some compasses allow the scale to be adjusted to compensate for the local magnetic declination; if adjusted correctly, the compass will give the true bearing instead of the magnetic bearing. The modern hand-held protractor compass always has an additional direction-of-travel (DOT) arrow or indicator inscribed on

7169-414: The cardinal directions can be calculated. Manufactured primarily for maritime and aviation applications, they can also detect pitch and roll of ships. Small, portable GPS receivers with only a single antenna can also determine directions if they are being moved, even if only at walking pace. By accurately determining its position on the Earth at times a few seconds apart, the device can calculate its speed and

7276-442: The case of the compass. The effect of ferromagnetic materials in the compass's environment can be corrected by two iron balls mounted on either side of the compass binnacle in concert with permanent magnets and a Flinders bar . The coefficient a 0 {\displaystyle a_{0}} represents the error in the lubber line, while a 1 , b 1 {\displaystyle a_{1},b_{1}}

7383-749: The compass and the placement of compensating magnets under the compass itself. Mariners have long known that these measures do not completely cancel deviation; hence, they performed an additional step by measuring the compass bearing of a landmark with a known magnetic bearing. They then pointed their ship to the next compass point and measured again, graphing their results. In this way, correction tables could be created, which would be consulted when compasses were used when traveling in those locations. Mariners are concerned about very accurate measurements; however, casual users need not be concerned with differences between magnetic and true North. Except in areas of extreme magnetic declination variance (20 degrees or more), this

7490-407: The compass card. For a table of the thirty-two points, see compass points . In the modern era, the 360-degree system took hold. This system is still in use today for civilian navigators. The degree system spaces 360 equidistant points located clockwise around the compass dial. In the 19th century some European nations adopted the " grad " (also called grade or gon) system instead, where a right angle

7597-409: The compass is located and if the force is acceleration or deceleration the compass will increase or decrease the indicated heading. Compasses that include compensating magnets are especially prone to these errors, since accelerations tilt the needle, bringing it closer or further from the magnets. Another error of the mechanical compass is the turning error. When one turns from a heading of east or west

7704-451: The compass is located on the surface of the Earth the angle between true north and magnetic north , called magnetic declination can vary widely with geographic location. The local magnetic declination is given on most maps, to allow the map to be oriented with a compass parallel to true north. The locations of the Earth's magnetic poles slowly change with time, which is referred to as geomagnetic secular variation . The effect of this means

7811-400: The compass to be "recharged" by sunlight or artificial light. However, tritium has a half-life of only about 12 years, so a compass that contains 120 mCi of tritium when new will contain only 60 when it is 12 years old, 30 when it is 24 years old, and so on. Consequently, the illumination of the display will fade. Mariners' compasses can have two or more magnets permanently attached to

7918-400: The compass was previously at is causing interference and should be avoided. There are other ways to find north than the use of magnetism, and from a navigational point of view a total of seven possible ways exist (where magnetism is one of the seven). Two sensors that use two of the remaining six principles are often also called compasses, i.e. the gyrocompass and GPS-compass. A gyrocompass

8025-410: The compass will lag behind the turn or lead ahead of the turn. Magnetometers, and substitutes such as gyrocompasses, are more stable in such situations. A thumb compass is a type of compass commonly used in orienteering , a sport in which map reading and terrain association are paramount. Consequently, most thumb compasses have minimal or no degree markings at all, and are normally used only to orient

8132-409: The correct local compass variation so as to indicate the true heading. ‹The template How-to is being considered for merging .›   A magnetic compass points to magnetic north pole, which is approximately 1,000 miles from the true geographic North Pole. A magnetic compass's user can determine true North by finding the magnetic north and then correcting for variation and deviation. Variation

8239-425: The development of models with extremely fast-settling and stable needles utilizing rare-earth magnets for optimal use with a topographic map , a land navigation technique known as terrain association . Many marine compasses designed for use on boats with constantly shifting angles use dampening fluids such as isopar M or isopar L to limit the rapid fluctuation and direction of the needle. The military forces of

8346-522: The expected type of environment. Traditionally, the chief mate stands a "4-8" watch : from 4 AM until 8 AM and 4 PM until 8 PM, in port and at sea, the chief mate is responsible to the captain for keeping the ship, crew, and cargo safe. On watch, the mate must enforce all applicable regulations, such as the International Convention for the Safety of Life at Sea and pollution regulations . In port,

8453-463: The ferromagnetic effects and a 2 , b 2 {\displaystyle a_{2},b_{2}} the non-ferromagnetic component. A similar process is used to calibrate the compass in light general aviation aircraft, with the compass deviation card often mounted permanently just above or below the magnetic compass on the instrument panel. Fluxgate electronic compasses can be calibrated automatically, and can also be programmed with

8560-478: The hawsepiper progression path has been made too difficult because of the cost in time and money to meet formal classroom training requirements. These critics assert that the newer requirements will eventually lead to a shortage of qualified mariners, especially in places like the United States. Sea captain A sea captain , ship's captain , captain , master , or shipmaster , is a high-grade licensed mariner who holds ultimate command and responsibility of

8667-420: The hiker has been following the correct path, the compass' corrected (true) indicated bearing should closely correspond to the true bearing previously obtained from the map. A compass should be laid down on a level surface so that the needle only rests or hangs on the bearing fused to the compass casing – if used at a tilt, the needle might touch the casing on the compass and not move freely, hence not pointing to

8774-457: The limitations of the radar/ARPA suite. Under the best conditions, the radar operator must be able to optimize system settings and detect divergences between an ARPA system and actual conditions. Information obtained from radar and ARPA must be treated with scrutiny: over reliance on these systems has sunk ships. The officer must understand system performance, limitations and accuracy, tracking capabilities and limitations, and processing delays, and

8881-536: The magnetic north accurately, giving a faulty reading. To see if the needle is well leveled, look closely at the needle, and tilt it slightly to see if the needle is swaying side to side freely and the needle is not contacting the casing of the compass. If the needle tilts to one direction, tilt the compass slightly and gently to the opposing direction until the compass needle is horizontal, lengthwise. Items to avoid around compasses are magnets of any kind and any electronics. Magnetic fields from electronics can easily disrupt

8988-647: The magnetic pole the compass will not indicate any particular direction but will begin to drift. Also, the needle starts to point up or down when getting closer to the poles, because of the so-called magnetic inclination . Cheap compasses with bad bearings may get stuck because of this and therefore indicate a wrong direction. Magnetic compasses are influenced by any fields other than Earth's. Local environments may contain magnetic mineral deposits and artificial sources such as MRIs , large iron or steel bodies, electrical engines or strong permanent magnets. Any electrically conductive body produces its own magnetic field when it

9095-418: The map to magnetic north. An oversized rectangular needle or north indicator aids visibility. Thumb compasses are also often transparent so that an orienteer can hold a map in the hand with the compass and see the map through the compass. The best models use rare-earth magnets to reduce needle settling time to 1 second or less. The earth inductor compass (or "induction compass") determines directions using

9202-415: The military is that one angular mil subtends approximately one metre at a distance of one kilometer. Imperial Russia used a system derived by dividing the circumference of a circle into chords of the same length as the radius. Each of these was divided into 100 spaces, giving a circle of 600. The Soviet Union divided these into tenths to give a circle of 6000 units, usually translated as "mils". This system

9309-465: The needle, preventing it from aligning with the Earth's magnetic fields, causing inaccurate readings. The Earth's natural magnetic forces are considerably weak, measuring at 0.5 gauss and magnetic fields from household electronics can easily exceed it, overpowering the compass needle. Exposure to strong magnets, or magnetic interference can sometimes cause the magnetic poles of the compass needle to differ or even reverse. Avoid iron rich deposits when using

9416-534: The north end of the needle are often marked with phosphorescent , photoluminescent , or self-luminous materials to enable the compass to be read at night or in poor light. As the compass fill liquid is noncompressible under pressure, many ordinary liquid-filled compasses will operate accurately underwater to considerable depths. Many modern compasses incorporate a baseplate and protractor tool, and are referred to variously as " orienteering ", "baseplate", "map compass" or "protractor" designs. This type of compass uses

9523-626: The payment of death benefits to a widow because she had established that her marriage at sea was lawful. However, in Fisher v. Fisher the involvement of the ship's captain was irrelevant to the outcome. New Jersey 's 1919 Bolmer v. Edsall said a shipboard marriage ceremony is governed by the laws of the nation where ownership of the vessel lies. In the United Kingdom , the captain of a merchant ship has never been permitted to perform marriages, although from 1854 any which took place had to be reported in

9630-464: The principle of electromagnetic induction , with the Earth's magnetic field acting as the induction field for an electric generator , the measurable output of which varies depending on orientation . Small electronic compasses ( eCompasses ) found in clocks, mobile phones , and other electronic devices are solid-state microelectromechanical systems (MEMS) compasses, usually built out of two or three magnetic field sensors that provide data for

9737-401: The reception of electronic signals. GPS receivers using two or more antennae mounted separately and blending the data with an inertial motion unit (IMU) can now achieve 0.02° in heading accuracy and have startup times in seconds rather than hours for gyrocompass systems. The devices accurately determine the positions (latitudes, longitudes and altitude) of the antennae on the Earth, from which

9844-483: The right to wear the laurus or corona laurèa and the corona navalis . Carrying on this tradition, the modern-day shipmaster of some nations wears golden laurel leaves or golden oak leaves on the visor of his cap. A skipper (sometimes also serving as the helmansperson , helmsman , or driver ) is a person who has command of a boat or watercraft or tug , more or less equivalent to "captain in charge aboard ship ." At sea, or upon lakes and rivers,

9951-533: The same way, a second officer usually holds a chief officer's certificate. To become a chief mate (unlimited) in the United States, one must first accumulate at least 365 days of service while holding a second mate 's license. Then, the candidate must attend approximately 13 weeks of classes or complete the assessments from NMC Policy Letter 04-02 and pass a series of examinations given by the United States Coast Guard. Similarly, one must have worked as

10058-604: The ship clear of danger in transit. Safety demands the mate be able to quickly solve steering control problems and to calibrate the system for optimum performance. Since magnetic and gyrocompasses show the course to steer, the officer must be able to determine and correct for compass errors. Weather 's profound effect on ships requires the officer be able to interpret and apply meteorological information from all available sources. This requires expertise in weather systems, reporting procedures and recording systems. The International Regulations for Preventing Collisions at Sea are

10165-483: The ship's log. A ship's master can, however, conduct a church service, regardless of any clergy aboard. Spanish and Filipino law, as narrow exceptions, recognise a marriage in articulo mortis (on the point of death) solemnized by the captain of a ship or chief of an aeroplane during a voyage, or by the commanding officer of a military unit. Japan allows ship captains to perform a marriage ceremony at sea, but only for Japanese citizens. Malta , Bermuda and

10272-443: The ship, making crew changes in port, and making accommodations for foreign crew members. Customs requirements can include the master providing a cargo declaration, a ship's stores declaration, a declaration of crew members' personal effects, crew lists and passenger lists. The captain has special responsibilities when the ship or its cargo are damaged or when the ship causes damage to other vessels or facilities. The master acts as

10379-477: The ship. There is a common belief that ship captains have historically been, and currently are, able to perform marriages. This depends on the country of registry, however, and most do not permit performance of a marriage by the master of a ship at sea. In the United States Navy , a captain's powers are defined by its 1913 Code of Regulations, specifically stating: "The commanding officer shall not perform

10486-449: The ship. Certification is given by national authorities, typically following completion of minimum necessary seatime and a course of approved training, based on the IMO model course. Many maritime countries have private or charitable organisations and associations for Master Mariners. These primarily include organisations to represent Masters in the industry. An example of a national organisation

10593-455: The skipper as shipmaster or captain has command over the whole crew. The skipper may or may not be the owner of the boat. The word is derived from the Dutch word schipper ; schip is Dutch for "ship". In Dutch sch- is pronounced [sx] and English-speakers rendered this as [sk] . The word "skipper" is used more than "captain" for some types of craft, for example fishing boats . It

10700-414: The techniques for survival at sea techniques in case it's necessary to abandon ship. Officers are trained to perform medical tasks, and follow instructions given by radio or obtained from guides. This training includes what to do in case of common shipboard accidents and illnesses. It is usual for a chief/first officer to hold a master's certificate so that he can take over from the master if necessary. In

10807-399: The term to describe themselves. Several merchant seamen's unions offer their membership the required training for career advancement. Similarly, some employers offer financial assistance to pay for the training for their employees. Otherwise, the mariner is responsible for the cost of the required training. Since the requirements of STCW '95 have been enacted, there have been complaints that

10914-479: The true bearing (relative to true north ) of its direction of motion. Frequently, it is preferable to measure the direction in which a vehicle is actually moving, rather than its heading, i.e. the direction in which its nose is pointing. These directions may be different if there is a crosswind or tidal current. GPS compasses share the main advantages of gyrocompasses. They determine true North, as opposed to magnetic North, and they are unaffected by perturbations of

11021-407: The use of built-in magnets or other devices. Large amounts of ferrous metal combined with the on-and-off electrical fields caused by the vehicle's ignition and charging systems generally result in significant compass errors. At sea, a ship's compass must also be corrected for errors, called deviation , caused by iron and steel in its structure and equipment. The ship is swung , that is rotated about

11128-466: The use of operational warnings and system tests. Emergencies can happen at any time. The officer must be equipped to safeguard passengers and crew. The officer must be able to take initial action after a collision or a grounding. Responsibilities include performing damage assessment and control, understanding the procedures for rescuing persons from the sea, assisting ships in distress, and responding to any emergency which may arise in port. The Chief Mate

11235-593: The vicinity, such as: These factors help the officer apply the COLREGS to safely maneuver in the vicinity of obstructions and other ships. Unfortunately, radar has a number of limitations, and ARPA inherits those limitations and adds a number of its own. Factors such as rain, high seas, and dense clouds can prevent radar from detecting other vessels. Further, dense traffic and course and speed changes can confuse ARPA units. Finally, human errors such as inaccurate speed inputs and confusion between true and relative vectors add to

11342-487: The watch focuses on duties such as cargo operations, fire and security watches, monitoring communications and the anchor or mooring lines. IMO regulations require the officer be fluent in English. This is required for a number of reasons, such as ability to use nautical charts and nautical publications , to understand weather and safety messages, communicate with other ships and coast stations, and to be able to work with

11449-608: Was adopted by the former Warsaw Pact countries, e.g. , the Soviet Union, East Germany , etc., often counterclockwise (see picture of wrist compass). This is still in use in Russia. Because the Earth's magnetic field's inclination and intensity vary at different latitudes, compasses are often balanced during manufacture so that the dial or needle will be level, eliminating needle drag. Most manufacturers balance their compass needles for one of five zones, ranging from zone 1, covering most of

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