Adventure Science: Kon-Tiki, 1950

Six Norwegians, a Swede, and a parrot hop onto a raft...and sail roughly 4,300 miles in 101 days. Not much of a punchline, is it? But it happened, and indeed, the resulting story is riveting. Beset by sharks, whales, flying fish, and a general lack of sailing experience (at one point part of the crew is almost lost when they take off in a dinghy to film the raft...and the raft rapidly floats away; at another point the cook sets the raft on fire when he falls asleep with the cookstove burning), the crew survived their journey from Peru to Tuamotu Islands (a Polynesian island). For the full story, I commend to you the 1950 documentary Kon-Tiki, which is available in its entirety on YouTube. It's perhaps the earliest "adventure science documentary" I've seen, in which scientists set off to do some amazing task and film the process themselves. The resulting hour-long film won the Academy Award for Best Documentary Feature in 1951. Here's the YouTube description of the film:

Intrigued by Polynesian folklore, Norwegian biologist Thor Heyerdahl suspected that the South Sea Islands had been settled by an ancient race from thousands of miles to the east, led by the mythical hero Kon-Tiki. Heyerdahl knew that the trade winds and ocean currents off the South-American coastline bear in the direction of Polynesia. Ridiculed by the scientific establishment, who had concluded that a voyage by aboriginal balsa raft from Peru to Polynesia was impossible, he decided to prove the possibility of his theory by duplicating the legendary voyage. The ensuing expedition was hailed as one of the most fantastic feats of daring and courage of its time.

Read more from Wikipedia. Also, don't miss The Kon-Tiki Museum!