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III. NAVIGATION 



In a general way, the sea, as a high road for commerce, now 

 serves man's purposes adequately. But now and then, even today in 

 the era of full-powered steamers, and elaborate safety devices, we 

 have brought home to us in a tragic way that the sea has its dangers. 

 We may be shocked to hear of a collision with ice, as chanced to the 

 Titanic in 1912; of the foundering of a steamer, its pl?tes stove in 

 by the force of the sea; or of the stranding of some ship put out of 

 her reckoning by an unexpected currant. The high rates of marine 

 insurance, as compared with insurance on goods in transit on land, 

 mirror the risk to property run on every passage; the risk to life is 

 equally grave. 



.A. STUDIES OF TIDAL AND OTHER CURRENTS 



Probably the greatest gain that Oceanography could offer in 

 cheapening, expediting and safeguarding commerce on the seas, and the 

 only considerable gain to be hoped from it in this respect at present, 

 would come from adding detail to our knowledge of ocean drifts and of 

 tidal currents, and of the depths of water off coasts not yet accur- 

 ately charted. 



The importance of ocean currents in ordinary day-to-day naviga- 

 tion is so obvious as to need no emphasis here. Ignorance of the 

 direction and velocity of the current is responsible for some of the 

 discrepancies between the true position of the ship as determined by 

 astronomical sights and that calculated for her by dead reckoning, 

 though log errors, bad steering, leeway, etc, , all enter in. A 

 recent example of the tragic effects an unrecognized drift may have 

 is afforded by th= difficulty that ships coming to the assistance of 

 the ill-fated V-stris had in finding her; the fact that she was more 

 than 30 miles from the calculated position, in a run of only two days, 

 being best explained in this way. Many wrecks have b_en caused by 

 ignorance of the direction and strength of the current near shore at 

 the time. 



It is self evident that to follow a favoring current hastens, to 

 st;m a contrary current retards passages. Thisisri^adi particularly true 

 off the east coast of the United Statt s by the proximity of the so- 

 called "Gulf Stream", the drift of which must always be taken into 

 account. Every hour wasted steeming against the current entails so 

 much extra cost; wherever it is possible to go with the drift fuel is 

 saved. And either small savings, or small losses, when cumulative, 

 reach staggering proportions in the course of years. This factor is 

 of far greater moment for the slow freighters, in which most of the 

 world's maritime commtfrce is carried, than for the fast passenger 

 liners which can often disregard the current. In parts of the South 

 Atlantic, Indian and Pacific Oceans we still lack sufficiently de- 

 tailed knowledge of v.vlocities and precise directions, of the eff-cts 

 on these of varying winds, and of seasonal variations, to allow 

 intelligent planning of routes for slow ships, even though the 

 general characteristics of the oceanic circulation are understood. 

 The aggregate economic loss from such ignorpnce, if measured in 

 dollars and cents, would be very large. Even if the current arrows 

 are true enough ts an indication of the mean direction, the actual 

 drift at any given date may differ widely from that shown, and this is 



