They won't buy it and put it in the shipping container that is sent out to re-provision. They will get the request on-board, wherever the ship is, and the F&B or Bar Manager will send a crew member out to look for it locally. As it appears to not be a mainstream brand (what do I know?) and it is not very expensive, I thought it might be easier to bring a bottle. They will probably find it if they are in the USA but overseas...who knows.