what is a groyne?
Introduction. A groyne is an active structure extending from shore into sea, most often perpendicularly or slightly obliquely to the shoreline. Adequate supply of sediment and existence of satisfactorily intensive longshore sediment transport are the sine qua non conditions of groynes efficiency.he wooden groynes are most often one-or two-row palisade structures. Effects of influence of the T-shape wooden pile groyne on the shore (local erosion on the lee side and accumulation on the other) are illustrated in Figure 3.