I things i need first aid kit to heal wounds when injured or maybe have some medicine to restore health and make up for lost water due to being in the desert

I things i need tent to have a place to sleep and rest. The same tent can block the harsh sunlight of the desert sun

I things water bottle to store fresh water while on a desert island and water is a very scarce thing and must be saved

The last one i chose is compass to be able to navigate when I'm on a large island looking for something, the compass can help me get back to the place of storage.