[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-668913-105":59,"doc-detail-668913-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","chapter-7-introduction-to-chart-work","Chapter 7 - Introduction to chart work","","Chapter 7 focuses on how chartwork supports safe navigation and watchkeeping by explaining how to interpret nautical charts. It covers the need for paper charts alongside modern satellite technology, the value of accurate position fixing, and practical precautions when using charts. The chapter explains chart projections, especially Mercator and Gnomonic, and describes measuring distance with nautical miles using dividers and parallels, including accuracy considerations. It also introduces key navigation tools and interpreting chart symbols from official sources.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":30,"@type":76,"position":81},"https://docshare.wps.com/document/technology/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/chapter-7-introduction-to-chart-work/668913/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/chapter-7-introduction-to-chart-work/668913.png","ImageObject",300,407,{"name":92,"@type":93},"Boyslovefans","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-03","2026-11-01",true,{"@type":102,"interactionType":103,"userInteractionCount":14},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"Why is chartwork essential for watchkeeping proficiency?","Question",{"text":112,"@type":113},"Chart interpretation underpins determining the ship’s position and recognizing navigational dangers. Without this understanding, the watchkeeper cannot accurately fix position or anticipate risks.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How do Mercator and Gnomonic projections differ for navigation?",{"text":117,"@type":113},"Gnomonic projection is used for ocean navigation and represents great-circle routes as straight lines, while Mercator is used for coastal and inshore navigation. Mercator distorts features and landmasses, and meridians do not converge at the poles.",{"name":119,"@type":110,"acceptedAnswer":120},"What tools and steps are used to measure distances on nautical charts?",{"text":121,"@type":113},"Use dividers to transfer distance from latitude scales, in the vicinity of the passage latitude. Measure using nautical miles and apply accuracy to the nearest appropriate calibration value.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},668913,1793520329,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":14,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":44,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":129,"read_time":143},1374410101428,"https://ap-avatar.wpscdn.com/davatar_3d24733baf745e90a7e4bdd5f77d97b2","CHAPTER 7  \nIntroduction to chartwork  \nThe first step towards proficiency in navigation to watchkeeping standards is understanding how to interpret a nautical chart. This fundamental knowledge will be the foundation GSPN XIJDI BMM UIF PUIFS TLJMMT PG UIF OBWJHBUPS DBO CF CVJMU VQPO􀀏 *G UIF DIBSU DBOOPUbe understood, then the ship’s position cannot be determined and dangers will not be recognised by the watchkeeper.  \nEven with today’s modern satellite technology, there is no substitute for the paper chart. Combined with a magnetic compass and traditional navigational tools, like dividers, parallel rulers, safe coastal navigation by a competent watchkeeper is always possible without the VTF PG NPEFSO OBWJHBUJPO FRVJQNFOU􀀏 3FNFNCFS UIBU VMUJNBUFMZ UIF TIJQ TIPVME CF TFMGsufficient in every way. The ability to determine the vessel’s position by use of a chart is vital JO UIF FWFOU UIBU UIF WFTTFM􀀈T (14 VOJU TIPVME GBJM􀀏  \nMany thousands of hours and huge amount of survey work has gone into each chart. Avoid GPMEJOH UIF DIBSU JG QPTTJCMF BOE LFFQ UIFN DPSSFDUFE BOE VQ UP EBUF BU BMM UJNFT 􀂉UIJT JTB TUBUVUF SFRVJSFNFOU XJUI SFHBSE UP UIF TFBXPSUIJOFTT PG UIF TIJQ􀀏 \"TJEF GSPN B SFBEZ SFGFSFODF DIBSU UIBU NBZ CF FYQPTFE UP UIF FMFNFOUT􀀍 EPO􀀈U VTF DIBSUT UIBU BSF MBNJOBUFE GPS XBUDILFFQJOH QVSQPTFT 􀂉 UIFZ BSF TMJQQFSZ VOEFS UIF QBSBMMFM SVMFST BOE JNQPTTJCMF UP VTF BQFODJM PO􀀏 -BNJOBUFE DIBSUT TIPVME OPU CF VTFE GPS QPTJUJPO EFUFSNJOBUJPO􀀏  \nChart interpretation  \nProjections—how the Earth appears on the chart  \nThere are numerous ways in which the Earth’s spherical surface can be projected onto a flat DIBSU BOE BMM IBWF TPNF FMFNFOUT PG EJTUPSUJPO􀀏 'PS OBWJHBUJPO BU TFB􀀍 UXP QSPKFDUJPOT BSFused: Mercator projection and Gnomonic projection.  \nGnomonic projection  \n5IF (OPNPOJD QSPKFDUJPO JT VTFE GPS PDFBO OBWJHBUJPO􀀏 *U JT DPNNPOMZ VTFE GPS QMBOOJOHQVSQPTFT UP FTUBCMJTI AHSFBU DJSDMF SPVUFT􀀈 XIJDI SFQSFTFOU UIF TIPSUFTU EJTUBODFT CFUXFFO positions, but would show up on the Mercator projection as a curved lines bulging towards the poles.  \n\n| | QPort Marine Services Est. 21 years\u003Cbr>Contract and Charter of Commercial Marine Floating Plant, Services and Logistics.\u003Cbr>Phone: 07 3893 0066 Email: [info@qportmarine.com.au](info@qportmarine.com.au)\u003Cbr>[www.qportmarine.com.au](www.qportmarine.com.au) | |\n| --- | --- | --- |\n\nChapter 7 Introduction to c h ar t work 111  \nC h a p ter 7 I n t r o d u c t ion to c h ar t work  \nC h a p ter 7 I n t r o d u c t ion to c h ar t work  \nMercator projection  \nThe Mercator projection is used for coastal and inshore navigation, it is an important projection for watchkeepers to be aware of. This method of projection distorts features and landmasses.  \nt Lines of longitude 􀀉NFSJEJBOT􀀊 SVO UISPVHI UIF OPSUI BOE TPVUI QPMFT􀀍 BOE DPOWFSHF XJUI FBDI PUIFS BT EJTUBODF JODSFBTFT GSPN UIF FRVBUPS 􀂉 think of the earth being cut into lemon wedges.  \nt Lines of latitude 􀀉QBSBMMFMT􀀊 USBWFM BSPVOE UIF &BSUI FBTU UP XFTU CVU OFWFS NFFU 􀂉 UIJOL PG UIF FBSUI CFJOH DVU JOUP B SFDUBOHMF SBUIFS UIBO B TQIFSF􀀏  \n\\#PUI MBUJUVEF BOE MPOHJUVEF SFQSFTFOU BOHVMBS EJTUBODFT􀀍 XJUI UIF BQFY PG UIBU BOHMF NFBTVSFE GSPN UIF HFPNFUSJD DFOUSF PG UIF FBSUI􀀍 JO UXP EJNFOTJPOT 􀂉 OPSUI􀀐TPVUI  \n􀀉MBUJUVEF􀀊 BOE FBTU􀀐XFTU 􀀉MPOHJUVEF􀀊􀀏 5IFTF BOHVMBS EJTUBODFT BSF SFQSFTFOUFE PO UIF DIBSU􀀏 The scale of latitude runs down either side and the scale of longitude runs across the top and the bottom. With a Mercator chart, meridians of longitude do not converge at the poles. The charts used for coastal navigation are a much larger scale, however, the same principle applies as they are still in Mercators projection.  \nMeasuring distance  \nThe unit of measurement at sea is the nautical mile and measuring distances on the chart using this unit is simple:  \nt 0OF EFHSFF PG BSD JT GVSUIFS EJWJEFE JOUP 􀀗􀀑 NJOVUFT􀀏  \nt 0OF NJOVUF PG BSD BU UIF &BSUI􀀈T TVSGBDF JT FRVBM UP POF OBVUJDBM NJMF􀀏  \n5IFSFGPSF POF EFHSFF PG BSD 􀀉NFBTVSFE GSPN UIF DFOUSF PG UIF &BSUI􀀊 JT ","cbCaiiBEP4r3OWoN","https://ap.wps.com/l/cbCaiiBEP4r3OWoN","pdf",499025,"English","# Introduction to chartwork\n## Chart interpretation\n## Projections—how the Earth appears on the chart\n## Gnomonic projection\n## Mercator projection\n## Measuring distance\n## Dividers\n## Parallel rules\n## Interpreting chart symbols","[{\"question\":\"Why is chartwork essential for watchkeeping proficiency?\",\"answer\":\"Chart interpretation underpins determining the ship’s position and recognizing navigational dangers. Without this understanding, the watchkeeper cannot accurately fix position or anticipate risks.\"},{\"question\":\"How do Mercator and Gnomonic projections differ for navigation?\",\"answer\":\"Gnomonic projection is used for ocean navigation and represents great-circle routes as straight lines, while Mercator is used for coastal and inshore navigation. Mercator distorts features and landmasses, and meridians do not converge at the poles.\"},{\"question\":\"What tools and steps are used to measure distances on nautical charts?\",\"answer\":\"Use dividers to transfer distance from latitude scales, in the vicinity of the passage latitude. Measure using nautical miles and apply accuracy to the nearest appropriate calibration value.\"}]","Chapter 7 - Introduction to chart work | PDF",23]