WAVE DIMENSIONS IN THE NORTH AND 

 BALTIC SEAS 



The following translated paper first appeared, in limited 

 issue, as Technical Report HE-116-150s Fluid Mechanics 

 Laboratory, University of California „ The paper is re- 

 produced here to bring the findings to the attention of a 

 larger group of research workers and others having an in- 

 terest in ocean waves „ The original paper "Beitrage zur 

 Frage der Grossee der in Nord-und Ostsee vorkommenden 

 Wellen" v:as prepared by Eo Mewes of the Deutsche Versuch- 

 sanstalt fur Luftfahrt, Eo Vo Institut fur Seeflugvresen, 

 Tferlin - Adlershof, October 1937 o 



Introduction 



ac Purpose of report » - The engineer designing ocean going craft 

 requires a knowledge of the conditions produced by the state of the sea. 

 Important are the specification of wave heights, wave length, and wave 

 periods. This report is to contribute to the knowledge of these wave 

 dimensions by reporting observations made in specific areas of the North 

 and aitic Seas (along German coast), 



bo Type of data used , - In the winter of 1936-37 observations of 

 the state of the sea were made and recorded by the captains of a number 

 of German lightships „ The project was sponsored and directed by the 

 Hydrographic Section of the Lilienthal-Gesellschaf t for aeronautical 

 research (Arbeitsgruppe fur Seegangsforschung, Lilienthal-Gesellschaf t 

 fur Luf tfahrtforschung). The information required by this organization 

 included estimation of wave dimensions and periods o A large part of 

 these observations are used in this report. 



Also the marine-aviation section of another German aeronautical 

 research organization, Deutsche Versuchsanstatt fur Luftfahrt (DVL) 

 has measured wave motion by instrument continuously since September 1936. 

 These measurements were made with instruments developed by this research 

 group in the &ltic Sea from the lightship FEIMAMBHLT and for short 

 periods from the lightships BORKMRIFF and AMRTOBANK in the North Sea, 

 Uiis recorded data has only partially been reduced and, consequently, 

 limited use is made of it here. 



Evaluation of Accuracy 



a„ Relative value of measurement and observation , - Generally 

 the results of measurements, with DVL apparatus must be considered 

 more reliable than visual observations which essentially are estimations. 

 But usable information may be obtained from such observ'^ations of wave 

 dimensions since the relative ease of procurement and evaluation per- 

 mits the collection of such observations on a greater scale. The great- 

 er part of the data used in this report was obseirved rather than measured, 



