It‘s a shame I had to scroll down so far to see the second half of your explanation. The point about production is why trying to outlaw alcohol is so much more insane than trying to outlaw any other drug. The moment an apple leaves its tree, it starts producing alcohol. There‘s a reason alcohol is ingrained in so many cultures: It gets created basically everywhere, with and without human interaction.
But that could mean the ship is actually a witch! And witches do have a history of bringing down bridges.