Can DACA approved DREAMers go on cruises?

As you know, I am strongly opposed to DACA approved DREAMers leaving the United States, even with advanced parole documents.  Yes, I understand that you may have to travel abroad using AP for business meetings or for humanitarian reasons or in some cases to exploit the loophole to let you adjust your status by wiping out your record of entry without inspection (EWI).  Other than that, I cannot think of any other good reason to risk your future by leaving the US border.  Despite this, I keep getting questions about what loopholes can the DREAMers exploit to study overseas (I mean, seriously, the whole world aspires to study in America, and you want to go elsewhere?) or party somewhere or attend weddings.

Passport may not be needed but proof of citizenship is:  One of these frequent questions is about cruises to the Caribbean Islands, like The Bahamas.  The thing is that some of the advertisements for these cruises tend to add "no passport needed" phrase to attract those US citizens who do not have passports (which were not needed for travel to most neighboring countries until recently but are now needed for almost all travel) but these are very limited number of cruises that follow limitations on where they start and end (closed loop).  Also, while American citizens may not need a passport, they need proof of their citizenship, like a birth or naturalization certificate.  In other words, the statement is misleading.

Overseas trips are risky for everyone, including US citizens:  Another important point to note is that any travel (particularly overseas travel) is sometimes full of surprises.  So let us say that you go on one of these cruises and the ship breaks down.  The cruise line will most likely put you on a flight back home (rather than a ship, but even if it does that, the ship maybe going to another port and from there the cruise line will arrange additional transport to bring you by land or air to the point of origin but now it is no longer a closed loop cruise and a passport is mandatory to disembark at the port of entry) and in that case you will need a valid passport with visa to the United States to enter the country (and this is also a cautionary message to US citizens that while they might be able to complete a closed loop trip without a hitch in most cases, in case of emergency, they will need a passport -- of course, you can approach the local US embassy to get a travel document but it might take days to get one and if you are sick and want to get back home right away, it's not very helpful to be traveling to the consulate while you are already very sick). 

The net result is that everyone will be better off leaving the US only with a valid document to be able to reenter the country, DREAMers simply cannot afford to leave the US to a foreign destination without proper paperwork.  By the way, cruises to destinations like Puerto Rico, Alaska, US Virgin Islands, and Hawaii are all US land and you can freely visit them without a passport or visa to the US, unless the journey is through another country that may insist on a transit visa (for example, some flights to Alaska go via Canada and Canadians will typically not grant visas to those aliens who are in the United States illegally).