On the Meteor Expedition wave heights were measured froLi 

 otereophotogrammetric pictures and these wave heights were 

 compared to simultaneous estimates of the state of the sea 

 made by the ships' officers. A coiuparlson of the two sets of 

 observations led to the assigmiLent of the wave heights which 

 are given in Table III, column 5. 



In view of the discrepancies between different systems for 

 describing sea state, only a tentative assignment of wave heights 

 (in feet) to the different terms of the Douglas Sea Scale is 

 given in Table III, column 6. It should be noted that this 

 assignment Intends to relate the wave heights as obtained from 

 Plates II and V to the terms of the Sea Scale. Considerable 

 weight has been given to the Meteor data and to the fact that 

 for low waves the observed wave heights are in general too 

 lov/. If the latter feature is taken into account there is no 

 great discrepancy betv/een the values of the Admiralty Weather 

 Manual (Table III, column 4) and the values introduced here 

 (coluiiin 6). The validity of the tentative assignment can be 

 tested by comparing reports of the state of the sea to values 

 derived from wind fetches and durations as determined by means 

 of weather maps. 



In columns 7 and 8 are stated tlie corresponding wind vel- 

 ocities based on fetches of 500 loiles and durations of 24 hours. 



The frequency and direction of different states of sea in 

 certain parts of the oceans, as v;ell as the frequency and 

 direction of swell, are given on H. 0. charts Kos. 10; 712A, 

 C, and E. 



34 



