I will first of all have pocket knife and match with me as pocket knife will help cut wood and match will light it and pocket knife will also help me cut coconut from trees in the island if there are any so that I can eat and get water from it too. I will be a tent for shelter, 4th would be binoculars from which I can look if I can see any ships approaching and ask for help. 5: would be boat with rows so that I can row my way to a land with help on it. that would have to be inflatable of course as u said in knap sack.