Seriously:

Within the bottle, a postcard written in June 1914 by Captain CH Brown of the Glasgow School of Navigation promised the finder a reward of 6 pence. It had been part of a scientific experiment in which 1,890 such bottles were released, in a bid to chart currents around Scotland.

Even odder, the person who found this 98-year-old message worked on the same boat as a man who found a 93-year-old message back in 2006. The bottles were part of an early-20th-century research project to map Scotland's sea currents.