Somewhere I have a book, can remember the author or title (or what I had for breakfast) right now, but this guy, from England, walked all the way around Baja California, Mexico, following the coastline almost all the way. He got a large portion of his drinking water by that method. He carried a regular old stainless steel "tea pot" (like you heat water on the stove with, little whistle in the cap), and some stainless steel tubing. Using sea water and drift wood, it worked like a champ...