The numerous publications are mostly restricted in presenting observa- 

 tions made in the field or the laboratory. With exception of a few 

 purely empirical equations, which describe only particular measurements, 

 no attempt has been made, at least to the writer's knowledge, to derive 

 basic relationships which will constitute the basis of a quantitative 

 treatment. In this paper we will try to analyze separately the indivi- 

 dual mechanisms that constitute the overall phenomenon of sediment trans- 

 port by ocean waves. After each phase of the problem is well-described 

 and understood, the desired relationships will be developed based on all 

 available theoretical concepts and empirical evidence. A more detailed 

 description of our objective is given in the following section. 



2. FORMULATION OF THE PROBLEM 



It has been observed that loose sediment is moving in considerable 

 quantities near and along the ocean floor even in relatively deep water. 

 This motion cannot be attributed to the action of ocean currents because 

 the flow intensity of these currents is usually very low and the hydro- 

 dynamic forces associated with it are not sufficient to overcome the 

 forces resisting motion. It is evident, therefore, that the mechanism 

 mainly responsible for this motion has its origin in the oscillatory flow 

 near the bed which is caused by the surface waves. It is obvious that in 

 general there is no net transport associated with this motion since the 

 particles oscillate more or less about their mean position. The claim set' 

 forth is that the hydrodynamic effect of this flow is to relieve the part- 

 icles of all or part of their weight so as to bring them to a state of 

 incipient equilibrium. At this state any incidental secondary flow or 

 current, no matter how weak, will be able to set the particle in motion. 

 The problem now may be defined in a more precise form. An oscillatory 

 motion is induced by the surface waves on the boundary layer. It is 

 desired 



a. To develop an expression that describes the flow 

 field in the boundary layer. 



b. To determine the dynamic effect of this field on 

 the solid particles forming the bed. 



The individual results of these two phases of the problem will be com- 

 bined in a logical fashion to obtain a relationship by means of which it 

 will be possible to predict the pattern of the motion of solid particles 

 near the bed for a given set of wave characteristics and bed composition. 

 We proceed first with the study of the flow in the boundary layer. 



