Drinking seamen

Today, the bus system on my route into work crumbled beneath me, so I got the Tube. (Urgh)

When I arrived at Goodge Street station, I decided to throw caution to the wind and buy a sausage roll and a can of Coke from the shop next to the entrance. I didn't look carefully at the can till I got it to the office, but when I did, I discovered that it not only contained 10ml more liquid than a regular can, but it said in large letters around the top "EXPORT FOR MARITIME CONSUMPTION ONLY". I will award a prize (genuinely this time) for the most illuminating or funniest suggestion for why this may be.

DSC07256