A gigantic tidal wave will destroy much of the civilized world, but Admiral Harriman Nelson has a plan to stop it -- Seaview will set off a nuclear explosion at precisely the right time and place. Evil forces seek to destroy Nelson before he implements his plan -- in the chaos following the tidal wave, they hope to take over the world! Seaview's original Skipper is killed and it's Lee Crane from the US Navy to the rescue.