我
- A.Directly in line with the bow
- B.Side by side，with their lines on the port and starboard side
- C.So that their lines form an angle
- D.On top of one another
- A.They occur when the Sun is at minimum declination north or south
- B.They occur when the Moon is at maximum declination north or south
- C.The difference in height between consecutive high or low tides is at a minimum
- D.They are used as the basis for the vulgar establishment of the port
- A.They occur only at quadrature
- B.They occur when the Moon is nearest the Earth
- C.They cause diurnal tides to become mixed
- D.They have a decreased range from normal
- A.shallow water
- B.deep water
- C.river
- D.tide
- A.freshets
- B.floods
- C.river flows
- D.seismic events
- A.ECDIS warnings and messages
- B.Hydrographic Office data
- C.Notice to Mariners information
- D.All of the above
- A.SEMIDIURNAL
- B.DIURNAL
- C.MIXED
- D.OSCILLATING
- A.Current can be determined by measuring the direction and distance between simultaneous EP and DR positions
- B.The drift of the current should be averaged out on a one hour basis
- C.After the current is determined，it should not be used for further plotting because it is an unknown variable
- D.The distance between a simultaneous DR position and fix is equal to the drift of the current
- A.Safe water mark
- B.Isolated danger mark
- C.Preferred channel mark
- D.Daymark of no lateral significance
- A.The objects lie in a straight line
- B.The vessel is inside of a triangle formed by the objects
- C.The vessel is outside of a triangle formed by the objects
- D.A circle will pass through your position and the three objects
