188 



NAUTICAL CHAET MANUAL 



T. Tides and Currents 



u. 



Compass 



High water 

 Higher high wafer 

 Low wafer 

 Low wafer datum 

 Lower low water 

 Mean fide level 



Mean sea level 



Elevation of mean sea level 



above chart (sounding) datum 

 Chart datum (datum for 



soundmg reduction] 



Spring tide 



Neap tide 



Mean high water springs 

 Mean high water neaps 

 Mean higher high water 

 Mean high wafer 

 Mean low wafer springs 

 Mean low water neaps 

 Mean lower low wafer 

 Mean low water 

 Indian spring low water 

 High water full and change (vul- 

 gar establishment of the port) 

 Low water full and change 

 Mean establishment of the port 

 Establishment of the port 

 Unit of height 

 Equinoctial 



Quarter-, Quadrature 

 Stream 



Current, general, with rate 

 Flood stream (current) with rate 

 Ebb stream (current) with rate 

 Tide gauge, Tidepole, 

 Automatic fide gauge 



Velocity: Rate 



Knots 



Height 



Tide 



New moon 



Full moon 



Ordinary 



Syzygy 



Flood 



Ebb 



Tidal stream diagram 



Place for which tabulated tidal 

 stream data are given 



Range (of fide) 



Phase lag 



Current diagram, with 

 explanatory note 



"I..., I fo 



30 '"'., 





Olg ^V- \^ 



% '•■■■(■• 



,.,.-v 



Compass Rose 

 The outer circle is in degrees with zero at true 

 north. The inner circles are in points and degrees with 

 the arrow indicating magnetic north. 



21 b rg Bearing 



22 True 



23 mag Magnetic 



24 var Variation 



25 Annual change 



25a Annual change nil 



Abnormal variation-, 

 Magnetic attraction 



27 deg Degrees (See E-20) 



28 dev Deviation 



