Where property on bluffs or cliffs is threatened, the placement of large rocks called riprap is a common method of protection. Individual rock must be extremely durable and large enough to withstand extreme wave action. They are usually granite or marble and weigh between 3-5 tons. Riprap must be high enough that waves do not break over the top of it. In addition, it should be placed on bedrock or in deep enough sand so it will not be undermined or collapse.

Riprap usually has a short life span because it is rarely applied according to the criteria mentioned above. Instead, rocks are typically dumped in the sand in front of endangered property under emergency conditions. A potential problem with incorrect use of riprap is that sand under the riprap can be scoured by wave action, and cause rocks to collapse and tumble onto the beach. Another problem occurs when one property owner constructs a barrier, but his neighbor does not. Over time, wave action becomes concentrated on the unprotected areas next to the riprap and erosion is likely to occur on the neighbor's property. Usually the best approach is to coordinate structures with neighbors and use multiple protection strategies.

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