How to obtain water when stranded at Sea Source of Water Method used  Remarks Sea water Use a  reverse osmosis  desalination kit if available. Floating solar still or a  Bag still A manual system will require  a lot of pumping and should only be done in the shade or cool of the night.  See our Solar Still Page Rain Catch rain in tarps or in other waterproof material and funnel into containers or tie it up like a rucksack. Expose any absorbent cloth to the rain and wring it out. If you are in a disabled or lifeboat and the bilge is clean (Wash with salt water, then bail it out before the rain reaches you) you can collect the rain water. Never allow your surroundings to become contaminated with waste or animal parts. If tarp or water-holding material has become encrusted with salt, wash it in the sea before using (very little salt will remain on it). Washing containers with salt water before storing water will help to disinfect them. Sea ice Melt clear sea ice or shave it if no heat source exists See remarks above for frigid areas Seaweed Bag type solar still See our Solar Still Page Fish As soon as you catch a fish you can eat it's flesh raw, or suck the moisture out, or place it in a piece of  cloth material and ring out the moisture. The fish can be  rubbed with crusted sea salt and dried for late consumption but only when you have a ready supply of fresh water.

Steven Callahan survived more than 2 months alone at sea in an inflatable raft. In January 1982, Callahan set sail from the Canary Islands on a small boat he built himself. The boat sank six days into the trip and Callahan was left adrift on a five-foot (1.5 meter) life raft.

With only three pounds of food and eight pints of water, and a solar still and a makeshift spear, Callahan managed to survive on his own until his rescue 76 days later. Read his memoir, "Adrift: Seventy-Six Days Lost at Sea"

 Water sources in different environments.

 

Environment Source of Water Means of Obtaining and/or Making Potable Remarks Beach Ground Dig hole deep enough to allow water to seep in; obtain rocks, build fire, and heat rocks; drop hot rocks in water; hold cloth over hole to absorb steam; wring water from cloth. Alternate method if a container or bark pot is available: Fill container or pot with seawater; build fire and boil water to produce steam; hold cloth over container to absorb steam; wring water from cloth. Desert           Ground in valleys and low areas at foot of concave banks of dry river beads at foot of cliffs or rock outcrops at first depression behind first sand dune of dry desert lakes wherever you find damp surface sand wherever you find green vegetation Dig holes deep enough to allow water to seep in. This requires a lot of energy. Place green vegetation in either a solar still or a bag still This will sweat out drinkable water. See our page that describes how to make and use these lifesaving devises In a sand dune belt, any available water will be found beneath the original valley floor at the edge of dunes. WIldlife and especially bird move toward water in the evening and away from water in the morning. So you can determine the approximate direction to a water source. Birds generally fly directly where as other animals may wander and graze. Birds can cove a lot of distance fast so it may be a ways off.   Cacti Cut off the top of a barrel cactus and mash or squeeze the pulp. CAUTION: Do not eat pulp. Place pulp in mouth, suck out juice, and discard pulp. Without a machete, cutting into a cactus is difficult and takes time since you must get past the long, strong spines and cut through the tough rind.

 Water sources in different environments (continued).

Environment Source of Water Means of Obtaining and/or Making Potable Remarks Desert (continued) Depressions or holes in rocks   Periodic rainfall may collect in pools, seep into fissures, or collect in holes in rocks.   Fissures in rock Insert flexible tubing and siphon water. If fissure is large enough, you can lower a container into it.     Porous rock Insert flexible tubing and siphon water.     Condensation on metal Use cloth to absorb water, then wring water from cloth. Extreme temperature variations between night and day may cause condensation on metal surfaces. Following are signs to watch for in the desert to help you find water: Animal trails lead to water. You should follow in the direction in which the trails converge. Signs of camps, campfire ashes, animal droppings, and trampled terrain may mark trails. Flocks of birds will circle over water holes. Some birds fly to water holes at  sunset. Their flight at these times is generally fast and close to the ground. Bird tracks or chirping sounds in the evening or early morning sometimes indicate that water is nearby.

If you do not have a reliable source to replenish your water supply, stay alert for ways in which your environment can help you.

 See our page that describes how to make and use these lifesaving stills.

Figure 6-2. The effects of substitute fluids.

Heavy dew can provide water. Tie rags or tufts of fine grass around your ankles and walk through dew-covered grass before sunrise. As the rags or grass tufts absorb the dew, wring the water into a container. Repeat the process until you have a supply of water or until the dew is gone. Australian natives sometimes mop up as much as a liter an hour this way.

Bees or ants going into a hole in a tree may point to a water-filled hole. Siphon the water with plastic tubing or scoop it up with an improvised dipper. You can also stuff cloth in the hole to absorb the water and then wring it from the cloth.

Water sometimes gathers in tree crotches or rock crevices. Use the above procedures to get the water. In arid areas, bird droppings around a crack in the rocks may indicate water in or near the crack.

Green bamboo thickets are an excellent source of fresh water. Water from green bamboo is clear and odorless. To get the water, bend a green bamboo stalk, tie it down, and cut off the top (Figure 6-3). The water will drip freely during the night. Old, cracked bamboo may contain water.

Wherever you find banana or plantain trees, you can get water. Cut down the tree, leaving about a 30-centimeter stump, and scoop out the center of the stump so that the hollow is bowl-shaped. Water from the roots will immediately start to fill the hollow. The first three fillings of water will be bitter, (alkaloids) but succeeding fillings will be palatable. The stump (Figure 6-4) will supply water for up to four days. Be sure to cover it to keep out insects.

Some tropical vines can give you water. Cut a notch in the vine as high as you can reach, then cut the vine off close to the ground. Catch the dropping liquid in a container or in your mouth (Figure 6-5). Mind you if the liquid that comes out has a strong musky odor or is milky avoid it as it may be an irritant or even deadly

The milk from green (unripe) coconuts is a good thirst quencher. However, the milk from mature coconuts contains an oil that acts as a laxative. Drink in moderation only.

In the American tropics you may find large trees whose branches support air plants. These air plants may hold a considerable amount of rainwater in their overlapping, thickly growing leaves. Strain the water through a cloth to remove insects and debris.

You can get water from plants with moist pulpy centers. Cut off a section of the plant and squeeze or smash the pulp so that the moisture runs out. Catch the liquid in a container.

Plant roots may provide water. Dig or pry the roots out of the ground, cut them into short pieces, and smash the pulp so that the moisture runs out. Catch the liquid in a container.

Fleshy leaves, stems, or stalks, such as bamboo, contain water. Cut or notch the stalks at the base of a joint to drain out the liquid.

The following trees can also provide water:

 

• Palms. Palms, such as the buri, coconut, sugar, rattan, and nips, contain liquid. Bruise a lower frond and pull it down so the tree will "bleed" at the injury.

   

• Traveler's tree.  Similar to a Giant Bird of Paradise , this tree has a  sheath at the base of its leaves in which water collects.  Drill into the leaf bases or fronds (with a knife) and collect the water that pours out, can be a substantial amount.

   

• Umbrella tree. The leaf bases and roots of this tree of western tropical Africa can provide water.

   

• Baobab tree. This tree of the sandy plains of northern Australia and Africa collects water in its bottlelike trunk during the wet season. Frequently, you can find clear, fresh water in these trees after weeks of dry weather.