Chapter Page 



VI Pressure 45-58 



General 47 



Aneroid Barometers 47-49 



Barograph, Marine Type 49-53 



Three -Hour Pressure Tendency 54 



Coding and Entry of Pressure Data (app) on 



Form 615-5 54-58 



VII Temperature 59-67 



General 61 



Air Temperature Measurements 61-65 



Sea Water Temperature Measurements 66 



Coding and Entries of Temperature Data on 



Form 615-5 66-67 



VIII Clouds 69-80 



General 71 



Determination of Sky Cover 71 



Cloud Height 71-72 



Coding and Entry of Cloud Data on Form 615-5 . ... 72-80 



IX Waves 81-90 



General 83-84 



Wave Direction 84 



Wave Period 84-85 



Wave Height 85-86 



Coding and Entry of Wave Data on Form 615-5 . . . . 86-90 



X Ice 91-99 



General 93 



Ice Observation 93-94 



Coding and Entry of Ice Data on Form 615-5 94-99 



OBSERVATION TABLES 



Table 



1-1 Elements of the Code 8 



3-1 Determination of Wind Speed by Sea Condition 22 



3-2 Apparent Wind Speed 23 



4-1 Distance to Object on the Horizon at Sea 31 



5-1 Intensity of Rain 39 



5-2 Intensity of Snow 39 



VI 



