INTRODUCTION 



The Conference of Brussels, called in 1853, was the first International 

 Maritime Conference ever held. It sponsored the idea that governments 

 should foster systematic weather observations on ships, and should prepare 

 and publish charts of the prevailing winds, ocean currents, average sea and 

 air temperatures, and tracks of dangerous storms based on the additional 

 data. With the introduction of radio and fast ships, weather information be- 

 came of vital importance to safe and efficient ship operation. Many countries 

 began regularly scheduled weather forecasts to ships in nearby waters. 



Today, weather forecasts as well as charts are prepared from data 

 collected through ship observations. Forecasts of weather and sea condi- 

 tions are prepared to ship operation, air- sea rescue missions, over- water 

 air travel, military operations, etc. The need for accurate data is apparent, 

 since the forecast cannot be any better than the basic observation. 



Organization of the Manual. This manual has been designed to serve 

 primarily as a guide in the taking of weather observations at sea. It will be 

 helpful in using the manual to keep in mind that the material in it has been 

 organized to accord with the order of the various elements of the observa- 

 tion as they are entered in the basic Weather Bureau Form 615-5, "Ship's 

 Weather Observations." Each major element of the observation is completely 

 covered in a separate chapter. The first portion of each chapter is pre- 

 sented from the point of view of observing and evaluating the element without 

 reference to its ultimate use; and the second portion, from the point of view 

 of making a permanent record of it and preparing it for dissemination 

 (coding). 



IX 



