Is the USS Little Rock sleepover a Council sponsored event? If so, I believe that affords you some protection in the event of problems.
Has your Pack Committee discussed the event and shared all the details, including the sleeping arrangements, with the parents? If some are uncomfortable they can opt not to attend.
Our Pack has done sleepovers on battleships (USS Massachusetts, sleeping like the sailors in hammocks), museums (Boston Museum of Science and Plymouth Plantation, both very popular, folks bed down all over the floors of the exhibit halls), and cabins. All of these have