150 OUR HERITAGE THE SEA 



complicated by the tides upon a coast like ours ; and 

 this it is which renders local knowledge, such as is 

 possessed by the pilot, invaluable, indispensable. The 

 pilot must not only carry in his head a chart of the 

 coast, with the distances from point to point and the 

 shape of the bottom, but he must know how the tides 

 run in all weathers, how they are affected by the various 

 winds, and the difference between their rates at the 

 various times of the moon's age. Now this is know- 

 ledge which is only gained by experience, and although 

 many valuable books have been written as aids to the 

 mariner in respect of the tides' work, it nevertheless 

 remains true that nothing can give confidence in the 

 correctness of the course being steered on a dark or 

 a foggy night like a working experience of those 

 silent movements of the water. Even with long 

 experience there are some who never seem to be 

 perfectly at ease with the tides, as may be seen if 

 you care to watch the movements of the various 

 coasting sailing ships on a fine day. One man, by 

 his almost uncanny knowledge of the streaks of the 

 tide and how to steer so as to get into them, will be 

 observed to slip along past all his competitors, his 

 course being, to all appearance, a most erratic one, 

 yet perfectly calculated to get the utmost advantage 

 that the tide can give him, while other men, who have 

 never mastered more than the broad principles of tide 

 work, even though their experience may be longer, 

 must be content to come tailing along behind the 

 knowing one. 



Of course, there is also in certain places the 

 additional complication of current mingling with tide 

 and affecting it, and, as the current is liable to be 



