>>Come up with some sort of evaporative desalination method using coconut shells?
Depends - if you have enough coconuts you just drink the coconut water until rescued. If there is anything else edible on the island you eat that, water from plants will help.
The second option is capturing rainwater, assuming you're in a place with rain.
Third is boiling water to get rid of the salt(you need to capture the steam on a piece of cloth, wring it into another container, but it's probably going to be the fastest option).
Of course this is assuming you have any materials from your ship, which I assume these guys did? You'd at least need a metal pot or a metal sheet that you can bend into the right shape.
But yeah in general without access to at least some kind of container where you can boil water(maybe a rock of a right size would work?) you'd be generally screwed.
I think the final desperate option is to just try and dig down and hope you hit water and that it's not salty.
> if you have enough coconuts you just drink the coconut water until rescued
Coconut water has high levels of potassium, and in excess, has been noted in case reports to cause severe hyperkalemia. This link has more information:
> A 42-year-old black man without any medical history presented to our hospital after a syncopal episode. He was playing tennis outdoors all day in temperatures in excess of 90° Fahrenheit. He reported drinking a total of eight 11-ounce bottles of coconut water throughout the day. He experienced the sudden onset of lightheadedness and was witnessed to have lost consciousness
In the hole you dug, so on top of whatever soil or sand you dug into and filled with stones/rocks. You fill the hole with water after the fire has died down and use the residual heat in the stones.
You can't make a soup this way, but you should be able to make some steam -- I think.
I've never tried planting trees in sea water, but what if you tapped the tree as if it was maple syrup... would the sap still contain salt? Although I'm guessing that doesn't work on every kind of tree.
Depends - if you have enough coconuts you just drink the coconut water until rescued. If there is anything else edible on the island you eat that, water from plants will help.
The second option is capturing rainwater, assuming you're in a place with rain.
Third is boiling water to get rid of the salt(you need to capture the steam on a piece of cloth, wring it into another container, but it's probably going to be the fastest option).
Of course this is assuming you have any materials from your ship, which I assume these guys did? You'd at least need a metal pot or a metal sheet that you can bend into the right shape.
But yeah in general without access to at least some kind of container where you can boil water(maybe a rock of a right size would work?) you'd be generally screwed.
I think the final desperate option is to just try and dig down and hope you hit water and that it's not salty.