After the Vietnam war, Vietnamese farmers recycled thousands of external fuel tanks from U.S. aircraft to create makeshift river boats and canoes.
Drop tanks significantly increase the fuel capacity of a fighter, but they also add drag and make the aircraft less maneuverable. They are jettisoned when empty or when a fighter jet had to engage in air-to-air combat, or evade an incoming missile.
Several thousand drop tanks were jettisoned over Southeast Asia during the Vietnam War.
For farmers and fishermen living in isolated areas, the dropped drop-tanks literally were gifts from above
Royal Jet Inc of Alhambra, California (that’s one of their identification labels below) produced the tanks in clamshell halves that nested together for economical shipping. Once delivered to an air base, the halves were snapped together and secured by a belt.
After being jettisoned during combat missions, Vietnamese found the tanks came apart just as easily as they were put together.
So remember, when life gives you fuel tanks, you make canoes.