[Physkal]

>endured a six-week journey on which watermelons were his sole source of water. The writer, Major Edward Keith-Roach, complained about being unable to shave during that trip but couldn’t praise watermelons enough for saving his life and making the trek possible.

Was this ever common to do, using watermelons as a potable water supply?

[AlotOfReading]

They used to be (and still are for some groups) a primary water source for certain kalahari foragers during the dry season. It's a pretty unusual cultural adaptation to an extreme environment.