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CHAPTER X. ICE 



10000. GENERAL 



10010. The presence of ice at sea, including icebergs, is recorded as 

 part of the weather observation on Form 615-5 when ice is visible, or has 

 been observed at a point within a distance of 30 miles from the ship's position 

 at the time of the weather observation. 



10020. The reporting of icebergs or sea-ice in connection with the 

 weather report is not to take the place of the reporting of sea- ice and ice- 

 bergs according to the International Convention for the Safety of Life at Sea, 

 Reports requested by the United States Hydrographic Office, Coast Guard, 

 etc., will be submitted in addition to the weather report, 



10100. ICE OBSERVATION 



10110, GENERAL. The ice observation includes determination of the 

 kind of ice, the effect of the ice on navigation, the bearing of the ice- limit, 

 the distance to the ice- limit, and the orientation of the ice- limit, 



10120. KIND OF ICE, Ice is observed in terms of the most important 

 or prominent of the following conditions: 



10121. Ice-blink. When observed, determine the bearing of the blink. 

 Ice-blink is the white or yellowish-white glare on the sky produced by the 

 reflection of considerable areas of sea- ice or land- ice, which may be beyond 

 the range of vision. 



10122. New-Ice, A general term which includes the following types: 



10122.1. Ice-crystals (frazil- crystals) are fine spicules or plates of ice 

 suspended in water. 



10122.2, Slush (sludge) is an accumulation of ice-crystals which remain 

 separate or only slightly frozen together. It forms a thin layer and gives 

 the sea surface a grayish or leaden- tinted color. With light winds no ripples 

 appear. 



10122.3. Pancake-ice is composed of pieces of newly formed ice, usually 

 approximately circular, about 30 cm. (11.8 in.) to 3 m. (9.84 ft.) across, 

 and with raised rims, due to the pieces striking against each other, as the 

 result of wind and swell. 



10122.4, Ice- rind is a thin, elastic, shining crust of ice, formed by the 

 freezing of slush (sludge) on a quiet sea surface. Thickness less than 



