I think I'd be worried about food and survival first and taking pictures second. But I know what you mean.

I would take along my Zeiss Ikon Contax IIa with a 50mm f/1.5 Sonnar with some Agfapan APX 100.

By the way, I think you would be stranded "on" the island, rather than "in" it. Unless you were in a cave. In that case, I'd take the same camera but with some Kodak TMax 3200.