On April 28, 1947, Norwegian ethnographer and adventurer Thor Heyerdahl and five crew mates set out from Peru on the self-built raft Kon-Tiki to prove that Peruvian natives could have settled Polynesia. With Kon-Tiki, Heyerdahl sailed 8,000 km across the Pacific Ocean in a self-built raft from South America to the Tuamotu Islands to demonstrate that ancient people could have made long sea voyages, creating contacts between apparently separate culture
On the morning of 24 April, 1961, the Swedish warship Vasa was salvaged with a largely intact hull after it had sunk after sailing less than a nautical mile (ca 2 km) into its maiden voyage on 10 August 1628 at Stockholm harbour.
On April 15, 1912, 2:20 AM, British passenger liner Titanic sank after colliding with an iceberg in the North Atlantic during her maiden voyage from Southampton to New York City, US, causing more than 1,500 deaths.