Continual erosion necessitates frequent replenishment of the nourished beaches protecting communities along the Delaware Atlantic coast. Since conventional one-line models have failed to adequately predict the beach fill performance and the evolution of the beach profiles on four Delaware beaches, longshore and cross-shore sediment transport rates are inferred from detailed profile surveys using a two-line model. The model captures the dominant seasonal changes inherent to all 65 fixed profile lines which have been surveyed almost semiannually up to 11 times between 1998 and 2005. Cross-shore and longshore transport rates are shown to be of equal importance on these relatively steep beaches in a fairly energetic wave environment. © 2009 World Scientific Publishing Co. Pte. Ltd.