(1) Spilling. Spilling occurs when the wave crest becomes 

 unstable and flows down the front face of the wave producing an irregular, 

 foamy surface. 



(2) Plunging. Plunging occurs when the wave crest curls over 

 the front face of the wave and falls into the base of the wave producing 

 a high splash and much foam. 



(3) Surging. Surging occurs when the wave crest remains unbroken 

 while the base of the front face of the wave advances shoreward to break 

 on the shore. 



A scale of 1 to 6 was set up to record different individual and mixed 

 waves: (a) Type 1, spilling waves; (b) type 2, spilling and plunging; 

 (c) type 3, plunging; (d) type 4, surging; (e) type 5, surging and plung- 

 ing; and (f) type 6, surging and spilling. Spilling, plunging, and 

 spilling-plunging waves are prevalent at low and high tide conditions. 

 Surging waves (types 4, 5, and 6} are common at approximately 1 hour on 

 either side of high tide. 



e. Breaker Angle. Breaker angle was measured by a Brunton compass 

 to determine the azimuth of the wave crests as they approached the breaker 

 zone. The shoreline orientation of the study area was 350°; therefore, 

 breaker azimuths between 80° and 170° represent wave crests approaching 

 from the south and southeast and azimuths between 350° and 80° represent 

 waves approaching from the north and northeast. Azimuth readings were 

 converted to plus and minus acute angles to make breaker-angle readings 

 compatible with longshore current readings. Plus readings indicated 

 waves approaching from the north or northeast (azimuths between 350 and 

 80°); minus breaker angles indicated waves approaching from the south or 

 southeast (azimuths between 80° and 170°) (Fig. 2) . Azimuths of 170° or 

 350° indicate wave crests parallel to the shoreline (breaker angle = 0). 

 Breaker angles for the summer period varied between -40 and +10 with a 

 mean of -3.8°. In the winter period, breaker angles ranged from -8° to 

 +25° with a mean of +0.4°. Since ridges located on the low tide terrace 

 may cause wave refraction between low and midtide, breaker-angle measure- 

 ments may not reflect the actual breaker angle prevalent along the rest 

 of the study area. Under such conditions, it is necessary to use the 

 breaker angle of areas unaffected by local topography. 



2. Longshore Currents . 



Longshore current velocities were measured bihourly in the area 

 immediately landward of the breaker zone. Measurement of littoral trans- 

 port in this zone is known as beach drift (U.S. Army, Corps of Engineers, 

 Coastal Engineering Research Center, 1966). Current velocities were 

 measured in centimeters per second and given a sign value to indicate 

 longshore transport direction (- = north; + = south). A series of stakes 

 perpendicular to and extending seaward from the berm crest was used as 

 the starting point for the measurements. A plastic "whiffle ball" was 



