Poster for the Blue Network radio program <i><a href="https://en.wikipedia.org/wiki/The_Sea_Hound" class="extiw" title="w:The Sea Hound">The Sea Hound</a></i>, produced in association with the Office of the Coordinator of Inter-American Affairs
Captain Silver Syndicate, Inc.; art bears the signature "NEFF"
<a rel="nofollow" class="external text" href="https://www.raremaps.com/gallery/detail/36822/Captain_Silvers_Sea_Chart/Neff.html">Source</a>, reproduction offered <a rel="nofollow" class="external text" href="http://www.ebay.com/itm/Captain-Silvers-Sea-Chart-1942-Adventures-Sea-Hound-radio-WW2-map-POSTER-1950-/192176976763">here</a>