Coastal Resources - Let's say you got lucky and found a stream of fresh water pouring out into the bay or ocean where you are stranded. That sure beats the alternative, which is trying to desalinate the sea water. Since you can't boil the salt out of water, you'll have to create steam and capture the steam in a way that condenses it back into water. A high tech approach is to build a solar still, but you'll need clear plastic sheeting, and constant sea breeze can tear your solar still apart. The low tech option is even more laborious than fighting a solar still. You'll need to boil the salt water in an open vessel with a piece of cotton towel or cloth suspended a few inches over the container top. The steam will condense in the cloth, which you can wring out and drink. The down side is that it only catches a few drops at a time. Like I said, let's hope there's a stream or a lot of rain.