During the return from the Galápagos through the Sargasso Sea, Beebe once again failed to find the thick mats of Sargassum whose study had been one of the primary goals of the expedition. Searching for a way to satisfy his expedition's donors, Beebe hit upon the idea of documenting the marine life of the Hudson Gorge just beyond the shore of New York City. Applying the same techniques to studying the Hudson Gorge that he had used in the Galápagos, Beebe encountered a surprising variety of sea animals, many of which had previously been thought to be exclusive to the tropics.