The Sea Hound is an American radio adventure series that ran from June 29, 1942, to August 7, 1951. It began on the Blue Network June 29, 1942 – September 22, 1944, as a 15-minute serial for young audiences, featuring Ken Daigneau as Captain Silver of the ship The Sea Hound. In 1946–47 it aired on the Mutual Broadcasting System. The program expanded to 30 minutes on ABC radio June 21–September 2, 1948, alternating with Sky King. It last aired June 26–August 7, 1951, on ABC.Between 1942 and 1944 the series was produced with Nelson A. Rockefeller's Office of the Coordinator of Inter-American Affairs and was part of a national program to strengthen inter-American relations. Broadcast five times a week, the show featured Captain Silver and his sidekick Jerry hunting Nazi spies throughout the hemisphere. Every episode took place in a different Latin American country. Listeners were encouraged to write to NBC to request Captain Silver’s Sea Chart — a colorful map of the Americas that informed on the most important products and carried on its border pictures of outstanding heroes and flags of all the Latin America republics. Some 200,000 of such maps were sent out.