cruise liners are another story... though im sure the cruise line executives are motivated by money, they didnt get to be cruise line executives by being stupid... and nobody in their right mind plans a vacation or authorizes a holiday cruise into a war zone.
history has shown that the Brits were losing ships at a rate faster than their capacity for building replacements. so, they decided that if it would remain afloat, it would be used for transporting war materials, and/or troops.
many of the cruise liners of the era were specifically converted for this purpose, if you can confirm that the cruise liner is of enemy nationality, sink her!