Great point about garbage washing up on shore; it is virtually ubiquitous. I have found working flashlights (dive lights), an unopened can of Pepsi (didn't stay that way for long!) navigation charts, coils of yellow polyester rope, and glass and plastic net floats, just to name a few.

All in all, is you must be thrust into survival mode, let it be along a coast somewhere (add fresh water and you will be in pretty good shape).