The term 'SHIP FOR A COUPLES' CRUISE' can be summarized by the three letter solution ARK. This is a reference to the biblical story of Noah's ARK, in which God instructed Noah to build an ARK to save himself, his family, and two of every animal from a great flood. In modern times, the term 'ARK' has come to refer to any large vessel used FOR transportation, such as a CRUISE SHIP. Therefore, the term 'SHIP FOR A COUPLES' CRUISE' can be summarized by the solution ARK, which refers to a large vessel used FOR transportation, such as a CRUISE SHIP.