I am happy they were found, but I often wonder if I would live out my "Castaway on the Moon" fantasy or make a giant SOS if I found myself in this predicament.
Write SOS, then begin Castaway fantasy. If help arrives before you've had enough, ask if they could please come back and rescue you in a couple of weeks because you're trying to build a treehouse or setup irrigation channels for basic farming and you haven't even managed to spear your first fish yet.
If you did choose to live out the fantasy, it wouldn’t be for long. The island is small and consumable resources are quite limited.