The decision to bring alcohol on board a cruise ship is one that many people struggle with. The problem is made more difficult by the many different rules that cruise companies have. Some cruise lines will allow and even encourage passengers to bring alcoholic beverages on board. Others will not. The exact policy should be laid out in the cruise brochure under the heading Beverage Policy, but it is always best to check with the cruise line before trying to bring any alcoholic beverages on board in case rules have changed recently.
Typically, larger cruise ships and cruise lines will have restrictions on alcohol in place. Also many cruise ships that sell alcoholic beverages may place restrictions on what can and can not be bought on board for consumption. These rules are not made because the cruise line does not want to compete with the cost of shore purchased beverages. Most of the rules are made and enforced because of the laws under which the ship is granted license to serve beverages in the first place. There is also a crowd control issue involved. If the cruise line is in charge of passing out the alcohol, they can stop service to passengers who become unruly or dangerously drunk. If the passengers are allowed their own alcohol on board, that process becomes much more difficult for the crew.
Those who have been caught smuggling drinks onto cruise ships, have reported penalties ranging from confiscation of the beverages to being forced to pour the liquor out. There is also the possibility that a cruise line may refuse to allow a smuggling passenger back on board.
Much as airport security has increased, many cruise lines are now examining carry on luggage with increased scrutiny, and some passengers have even reported the use of dogs in some ports. For some cruise passengers, this makes smuggling more fun, but for most people it should be a warning.
The final decision about trying to bring alcohol is up to the individual passenger, but reading the brochures and asking a couple of questions beforehand can save a lot of trouble later. Why risk ruining a Great Lakes cruise by getting cough trying to smuggle alcohol on board? It is easier to find a cruise that allows or even encourages a BYOB policy. Or better yet, simply take one of the many cruises that serve alcoholic beverages and simply drinks from the ships' bar.