A.after every major hydrographic survey of the area covered by the chart
B.when there are numerous corrections to be made or the corrections are extensive
C.when a low-stock situation occurs and minor corrections are made
D.every two years to update the magnetic variation information
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A.Mercator projection
B.polyconic projection
C.orthographic projection
D.gnomonic projection
A.Summary of Corrections
B.Local Notice to Mariners
C.Daily Memorandum
D.Chart Correction Card
A.vertical distance from the chart sounding datum to the ocean bottom，plus the height of tide
B.vertical distance from the chart sounding datum to the ocean bottom
C.average height of water over a specified period of time
D.average height of all low waters at a place
A.Gray lines on the uppermost inset chart
B.Red lines on the main body of the chart
C.In parenthesis on the lines of equal magnetic variation
D.Annual rate of change is not shown
A.Chart No.1
B.Catalog of Charts
C.IMO Practical Navigator
D.IMO Light List
最新試題
The broken magenta lines（long and short dashes）in and around Mobjack Bay indicate（）.
The revision date of a chart is printed on which area of the chart? （）
A chart with a scale of 1:80，000 would fall into the category of a（）.
The only cylindrical chart projection widely used for navigation is the （）.
The soundings on the imperial chart are measured in（）.
The short-long dashed，magenta lines parallel to York River Entrance Channel mark（）．
What is NOT an advantage of the rhumb line track over a great circle track? （）
The soundings on the chart are based on the depth of water available at （）.
The survey information upon which a chart is based is found （）.
On chart，bearings to near objects should be used in preference to objects farther off，because（）.