As a result of shipwreck or getting separated from a group, you find yourself stranded on an island. Surviving is your focus and only consideration. You do not have to be an experienced outdoorsman, in order to take basic steps that will help keep you alive until rescue arrives.
Finding water is one of the top priorities and fundamentals of survival. You will want to find fresh drinkable water that can be boiled and/or filtered if possible. Always treat water before consumption while in the outdoors. If you must drink water without treating it first, look for pools or puddles of rain water that's fresh and collected on rocks or smooth surfaces.
Drinking water is crucial to your survival. You can survive by drinking water, consuming very little food, plants, fish, insects, reptiles, muscles, seaweed, coconuts, and small game animals. Water is needed to digest foods. Also water help regulate your core temperature.
NEVER DRINK SALT WATER!
Streams or springs are great sources to seek out. Running water is always a better option. Sometimes locating water sources proves to be difficult. You set up water collection devices to help create an artificial source. Use any containers you can find to collect rainwater or morning dew; each day, your hat or shoes can work as collection devices.
A solar still is another way of collecting condensation water, build a still by digging a hole. Place a can or other capture device in the bottom and surrounding the container with wet natural materials such as green grass, leaves or wet sand. Put a piece of plastic or vinyl material over the hole and weight it down with rocks; put a single small rock in the center to weight it down, forming a cone or funnel shape. Water will collect and drip into the container.
When selecting a shelter spot within your survival camp, look around the island for places that shield you from the elements of location and weather; if you have found fresh water, put your shelter within reasonable hiking distance. Also look for natural materials that are close to camp the enhance the shelter. You want your shelter to shield you from the sun, wind, rain, ocean spray, blowing sand. Also put the shelter far enough on the beach to avoid high tide.
Take whatever water craft you have that brought you to the island and lean it on one side to build a hasty shelter. You can lean it up on it's side against a tree or rocks. Also remember to tie down your raft or boat to avoid damage or drifting in currents.
Another option is a lean-to shelter. Use what nature provides, place tall branches against a solid base and covering them with leafy branches to create a wall that will keep out water, wind and sun. It's a good idea to build your shelter on or in view of the beach so you can run out quickly to signal passing boats or planes.
Food is an important consideration on a deserted island, but you must be careful about what you ingest. Fish provide protein and calories, and you can lay them to dry in the sun. You can sharpen a stick to spear fish or make your own pole using a shoelace, a stick and a makeshift hook out of a safety pin or piece of wire. If fishing yields no results, look for recognizable fruits first, like coconuts or plantains. You can also safely eat ants (make sure they are dead first), grubs and grasshoppers. Don't risk your life eating questionable berries, mushrooms or plants.