Survival on a desert island largely depends on the characteristics of the islands; its size; saturation of resources; natural area, which is an island; the time of year. From all of these factors depends on how long you can survive while waiting for rescue.
The larger island – all the better. On the big island will certainly be sources of water. Big Island, with a variety of terrain and conditions, represents an abundance of a variety of resources: food; materials for the raft and shelter, weapons and household appliances; firewood. In a large, resource-rich island can live independently for a long time. The resources will not be a limiting factor. Only you will decide to try to swim away from the island, or to stay and wait for help.
Small island – not very favorable place for the long-term survival. On these islands may not even be open sources of fresh water. Resources are usually limited. On a small island you can not build a full cover for the long term. Stocks of food quickly exhausted. You will be put before the fact: to escape from the island of the sea, or die due to lack of resources.
Of course, it is one thing if you were in a warm, tropical island – else if Polar Island, the taiga and the frost by –40. In fact, for a long time you can survive the harsh conditions in the northern islands. Enough to have warm clothes, shelter serious hut (complete chalet or a suitable cave). Of course on a tropical island are pluses and minuses; on a cold, northern – their. Warm jungle, though warm, but fraught with dangers such as mosquitoes, and various tropical diseases like malaria. But in the north the cold, scurvy, beriberi, a lack of plant foods.