When considering a dock project, google some version of the question:

“What does a seawall cost?”

“The City surveyed a number of seawall contractors. Seawall contractors quoted $650-$2,000 per linear foot, depending on the depth of the waterway materials used and location of the seawall.
In addition, engineering and permitting services were quoted as $5,000- $7,000 per job… cost will vary by the type and condition of the seawall in question.”