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cised when approaching icebergs and soundings should be continuous, 

 since submerged projections caused by overcutting may endanger the 

 vesseL 



If hove-to in pack ice in heavy weather, always place the vessel with 

 the stem against a floe and use the engines to hold the vessel up into 

 the wind. If the vessel falls off or drifts, serious damage may be sus- 

 tained from grinding, surging floes. Sometimes there is no polynya 

 or channel in which to heave to. Often in the pack, old ice is integi-ated 

 by a film of young ice. Under such circumstances, it is prudent to 

 heave to in the young ice where its soft texture will buffer the vessel 

 against encroachment by old ice. 



On approaching snow-covered land from ice-free waters the j'ellow- 

 ish landblink is usually observed before the land is raised above the 

 horizon. On many of the coasts of Antarctica a belt of pack ice is 

 found from 20 to 60 miles off the shore, with a belt of ice-free water 

 along the shore. When coasting inside this belt the mariner must 

 maintain an alert Avatch on its movements. An onshore wind will 

 drive the pack in quickly and place the vessel in danger of being set 

 on to the land. Under such circumstances it is usually better to put 

 to sea so as to meet the ice as far off the land as possible. If local con- 

 ditions are favorable, it may be possible to seek shelter in a bay or 

 behind an island or stranded berg. 



An accumulation of icebergs offshore invariably marks a shoal. The 

 water off a shore from which a line of icebergs extends is almost certain 

 to be foul. An island with a nearly continuous line of icebergs between 

 it and the shore is connected to the latter by shallow water or a sub- 

 merged ridge. If, on the other hand, the icebergs are concentrated 

 on the island and on the shore, leaving a wide space free of ice, this 

 space is probably clear of shoals. A shore fringed by glaciers or 

 studded with bergs inshore but free of ice to seaward, is considered 

 to be safe for a distance of about one mile from the shore. 



A bay in which icebergs are found has a channel leading into it. A 

 channel, the sides of which are bordered with icebergs with the center 

 clear of ice, may invariably be considered safe. 



Open water will usually be found during the summer months along 

 a coast where offshore winds prevail. 



The shii)'s Fathometer will not give a reading when ice is under the 

 ship or when the water beneath the ship is disturbed by backing down 

 or by the turbulence caused by ice floes being shoved around. A vessel 

 proceeding in uncharted coastal waters may minimize the risk of 

 grounding by having a boat equipped with a portable echo-sounder 

 scout ahead. 



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