The name "S.S. Minnow" was actually named after Newton Minow and was chairman on the FCC in 1961. He made a speech and called television "America's vast wasteland." The boat was named after the man who, Sherwood insists, "ruined television." Minow gave networks authority and placed the power of programming in the hands of the networks. He did this after Gilligan's Island was started.
There were actually four S.S. Minnows used on the show. The first Minnow was purchased and towed out to Kauai and used in the beach scenes. The second one was a rental they used in the opening credits at the Honolulu Harbor. It showed the crew boarding and then showed it sailing out to sea. The third was filmed in the opening credits of the second season at Marina Del Rey in Los Angeles. The fourth one was built for CBS Studios and is shown at the Lagoon in the second season opening credits.