Okay. You just washed up on a small island with no apparent source of fresh water and all you have is a PSK or your EDC plus PSK. You can build shelter from plants. You can fish or trap sea creatures for food. You might get lucky and have a few cocunut trees or various edibles.

With the exception of rain and dew collection what do you do for fresh drinking water?

You might have one trash bag to build a solar still. You would have to construct away from the tide. You would have to haul plenty of water to keep it going. Would this be enough to keep you alive?

You might get lucky and have some kind of foilage to put a transpiration bag on.

In the long run you might be stuck on that tiny island for a long time. Remember "Cast Away" The only drinking water Tom Hanks had was rain water he collected.

I got a couple of ideas

1. Collect water from bamboo stems
2. If you use your wire saw and do manage to cut a banana tree down (about 60cm from ground level). Make a bowl shape in what is left standing up. The tree will continue to suck up fresh water for at least 24hours. Collect and consume.
3. The top of (young) palm trees are edible and very tasty. These also contain a lot of liquid.
4. Collect water from plants that have a flower like a naturally shaped "bucket".
5. You could use an Indian well in saturated ground

Keep watching the distillation posts.

Hope this gives you some ideas.

Reinhardt

If you were to build a solar still, there's no reason why it should be away from the shore. The still purifies the water therefore the more saturated the ground, the more effected the still. Is this not correct? <img src="images/graemlins/crazy.gif" alt="" />

If you build it below the waterline of the high tide, the salt water will flood your still and contaminate your purified water. You could also loose your plastic sheet. This is why you might wish to keep a little distance to the waterline.

It all depends...

If there's a LOT of vegetation, trees (other than mangroves) and such, then there has to be quite a bit of fresh water, somewhere. You might have to dig for it, use seeps until you find better sources. Finding the lowest path the water would take back to the sea can't be far off.

I don't carry enough plastic for a solar still in either EDC or PSK, so that's outside the rules. You'd be lucky for one to survive a storm or two, anyway.

People have survived for months drinking only the blood of sea turtles and the occasional bird. Blood is far less saline than seawater, and will keep you alive, if you can get enough of it.

But.. there's a reason they call them "desert" islands, and if any large island is unpopulated, there's probably a reason for that as well. There may be enough to sustain one person but not a community... but there may not. You can't survive every possible scenario, and sometimes "no fresh water" is really NO fresh water.

Some new reverse-osmosis desalination systems use amazingly little energy, and may actually change the definitions of what's "inhabitable" or not... but it's nothing you're going to have in a pocket.

What is an Indian Well?

Digging sounds like a good idea. I'd hate to move a ton of sand from the wrong spot. This is one idea where I need to hear from all experts. Where do I dig?

In order to make an Indian well you need to find saturated ground. Dig about half a metre down and wait for water to rise. But the first water is not good enough for you so skip that out. Then clearer water will come through. Let this settle for about 30min so everything murky will have gone to the bottom. Make sure when you skip the fresh water out you do not disturb the bottom.
If water doesn't flow well enough into the hole use a stick to poke the sides in.

Another thing you can do is dig on the beach when it is low tide. There will be fresh water as this is lighter that salt water. Make sure you don't dig too deep or else you will get to salty water again.

Also check for fresh water trickes in rock lines and holes in trees.

Reinhardt