 Admiral Guest allowed it to be photographed by the news media, allowing the world at large its first peek at a thermonuclear bomb as it sat secured on the fantail of the submarine rescue ship USS "Petrel".Although both were put into service in 1964, the smaller "Alvin" was to have a much longer life.As of 2017, the "Alvin" is still in active service, operated by the Woods Hole Oceanographic Institution.