Locate a full-grown banana or plantain tree.
Use a knife or sharp rock to cut the top of the tree completely away, leaving just one foot of the stump. Banana and plantain trees aren’t particularly tough, so the cutting shouldn’t be too difficult.
Use the knife or the sharp rock to carve a bowl out of the top of the remaining stump. It should be about 6 inches deep in the middle, and curve up at the sides, just like a regular bowl.
The bowl will soon fill up with water–all by itself. Once the bowl is filled, empty all of the water without drinking any. This first bowl of water will be bitter and not drinkable.
Repeat Step 4 twice more. You should now have emptied the first three bowls of water without drinking any.
After the bowl has filled a fourth time, drink to your heart’s content. This water should be fresh, drinkable water–and your bowl should refill itself for at least three days. Now you can concentrate on shelter, food and your own rescue!
Don’t make your bowl too shallow–this is your repository of water, so make it at least 6 inches deep!