INTRODUCTION 



Slicks are streaks or patches of relatively calm surface water surrounded by 

 rippled water. The absence of wavelets in a slick gives it a glassy appearance in 

 contrast to the adjacent rippled water (fig. 1). 



From most angles of view, slick areas appear brighter than the surrounding 

 water during the day because the smoother area reflects the sky light better than 

 the rougher area. In the night, at locations where there is some ambient light, 

 slicks appear darker than the adjacent water because they reflect the black sky bet- 

 ter. They also appear darker in bright sunshine when the angle of view is such that 

 the light is directly reflected toward the viewer, because they do not produce a 

 glitter that results from the mutual reinforcement of the reflected rays from the 

 surrounding ripples. Schuleikin^ (see list of references on page 27) attributed 



Figure 1. Examples of sea surface slick. 



