During the course of his expeditions, Beebe gradually developed an interest in marine biology, ultimately leading to his 1930s dives in the Bathysphere, along with its inventor, Otis Barton, off the coast of Bermuda. This was the first time a biologist observed deep-sea animals in their native environment and set several successive records for the deepest dive ever performed by a human, the deepest of which stood until it was broken by Barton 15 years later. Following his Bathysphere dives, Beebe returned to the tropics and began to focus his study on the behavior of insects. In 1949, he founded a tropical research station in Trinidad and Tobago which he named Simla, and which remains in operation as part of the Asa Wright Nature Centre. Beebe's research at Simla continued until his death from pneumonia in 1962 at the age of 84.