二零二三年 优质公开课Navigation.pptx

 船长评估之《航海英语听力与会话》Navigation sNavigationcoursedepth (sounding)directionposition By headingis meant:the angle between the fore-and-aft lineand True North.SOUND HEADINGTRUE NORTH soundCOURSEBy courseis meant:the direction in which the vessel is steered.It is expressed in degrees. Do not confuse heading and course;HEADING AND COURSEheading constantlychanges due tosea- and wind influences andand steering errors. soundTRACKThe trackconsists of oneor a number ofcourse linesalong which thenavigator intends to proceed.WK GREAT CIRCLE COURSE (TRACK)DEPARTUREDESTINATIONA great circle course forms the shortest connection between two places on the earth. This implies that in (Mercator) sea charts the earth is not a sphere, but a square. soundDEPARTUREDESTINATIONA Rhumb lineis a line whereby all the anglesmade by the meridiansand the course lineare equal.RHUMB LINE (loxodrome) ssoundCOMPOSITE SAILING+Composite sailing combines the advantages of the great circle and the rhumb line:it will offer the shortest route, while the vessel can keep constant true directions. soundDRIFT AND CURRENTABDue to theinfluences of wind and currentdestination Bwill not be reached without any alterations of course. SsoundAB COURSE OVER GROUNDBy course over groundis understood the course that the ship will follow if no allowances are made for the effects caused by wind and sea(the vessel will end up in C).C soundABBy course made goodis understood the course that the ship will follow after allowing for the effects caused by wind and sea.COURSE (OR TRACK) MADE GOOD course over ground course made good sPOSITION Pilotage (coastal navigation);Cross bearing; The cocked hat; A running fix;Dead reckoning;Astronomical navigation; Satellite.sDetermining position PILOTAGEWhen sailing along the coast, compass- bearings of conspicuous objects are taken at regular intervals. PILOTAGEA CONSPICUOUS OBJECT (CONSPIC) is an object on land or at sea, which is mentioned and descri