Aerial view of the mooring channel for the Pan American World Airways "China Clipper" seaplanes at Alameda, California (USA), in 1937. Old U.S. Navy destroyers were sunken as a breakwater.
U.S. Navy
1937
<a rel="nofollow" class="external text" href="http://navalaviationnews.navylive.dodlive.mil/">U.S. Navy Naval Aviation News</a>/<a rel="nofollow" class="external text" href="https://www.history.navy.mil/research/histories/naval-aviation-history/naval-aviation-news/back-issues.html">(Archive)</a> <a rel="nofollow" class="external text" href="https://www.history.navy.mil/content/dam/nhhc/research/histories/naval-aviation/Naval%20Aviation%20News/1950/pdf/may54.pdf">May 1954</a>, p. 18.