Over the years, I have had the opportunity to walk beaches on the Channel Islands, and I have found:

1) fully working flashlights, plus numerous other items of scuba gear (nearly everything except a tank and regulator)

2) Discarded Navy nautical charts, in good condition

3) Unopened cans of beer (in the interests of science, they didn't stay that way very long!)

4) innumerable Japanese glass net floats

A friend has everything I have found beat all hollow. We were walking along, and he spied a boat paddle in a pile of debris. Pointing out that he had lost one from his skiff a few weeks earlier, he walked over to retrieve it - turns out it was the very same one he had lost about three miles away.

Question about the relict canoe that started this thread - Any idea of its age?