EKMAN. ON DEAD-WATER. Inorw. pol. EXP. 



of bluff design. One of my authorities has stated the contrary. Those that 

 are laden or of deep draught are always more liable than are light ones. 



Even after taking into account all the above circumstances, there is never- 

 theless something highly capricious about the appearance of dead-water; and 

 it is often impossible to understand why, in a certain case, a vessel has not 

 "taken dead-water", and in another case, why she did not escape its in- 

 fluence. A ship may, for instance, be towed without difficulty from one 

 place to another, but another similar or smaller ship being shortly after 

 towed the same way, will be so forcibly held by dead-water as scarcely to 

 be moveable from the spot. On another occasion a sailing-vessel or a vessel 

 in tow may be held by the dead-water, while other similar vessels, with less 

 or equal moving power, may pass quite near to her without being in the 

 least troubled by the phenomenon. 



Vessels apparently often "take dead-water" on account of the wind slacke- 

 ning or as a result of the vessel entering water-layers of a different character; 

 sometimes the cause of gelting free may likewise be put down to a similar 

 influence. But often the change cannot be explained by any perceivable 

 external cause. Often a vessel gets into dead-water while tacking, or on 

 account of bad steering, or when her speed is from any cause temporarily 

 slackened. If a sailing-vessel takes dead-water on account of the wind 

 slackening to below a certain strength, the wind, as a rule, must freshen to 

 above this strength to free the ship again. In general, when a vessels speed 

 is temporarily slackened and she gets into dead-water, she may be unable 

 to recover her head-way for some shorter or longer time, even when the 

 conditions for full speed are present again. 



Mariner's opinions of dead-water and its causes vary somewhat, and 

 to judge from their explanations of the phenomenon they generally acknow- 

 ledge they do not understand it. Most of my authorities, nevertheless agree 

 in the observation, that it depends on the existence of a surface layer of 

 fresh or brackish water. It is a general opinion, that "the fresh water sticks 

 to the vessel" and is dragged along with it on the top of the salt water, 

 thus impeding the speed — the fresh water on account of its forward motion, 

 has no influence upon the rudder. Other narrators declare that the phenomenon 

 is owing to the fresh water running as a surface-current above the salt 

 water; if a ship moves at a slow speed, the rudder becomes too much 



