When a decaying Russian satellite crashes on the island, the Professor uses a key component for a barometer. With that device, he learns that a massive wave is going to swamp the island. In desperation, the castaways lash their huts together into one structure in order to have any chance to ride the disaster out.

The slapstick adventures of hapless Gilligan, long-suffering Skipper and their gang of mismatched castaways, all stranded on an uncharted desert isle after their tiny ship hit stormy weather.