O.K. My $0.02 worth.
I believe that at the point that this passenger snuck liquor onboard the ship, which was a clear violation of the contract between aforementioned passenger and the cruiseline, argument could be made that he voided his contract with the cruiseline. At the point the contract was voided, the cruiseline had no further obligation to this passenger.
Since he was of legal drinking age and the contract between passenger and cruiseline is extremely well defined, they are not liable and have been released from any liability as a result of his own negligence or foolhardy actions. That coupled with the fact that the passenger voided out the contract by sneaking liquor on board, means . . . . . . (drumroll please)
The family and their bottom feeding attorneys are dead in the water (no pun intended)
Now, there is always some hungry attorney to take this waste of time case in the hopes that there may, by some miracle, be a payday at the end of this. The family may not realize how furtile this lawsuit is.
I work for a very large law firm in New York City. One of the richest in the country in fact. This is why companies like RCCL (not our client) pay law firms like the one I work for the really big bucks. RCCL will make mincemeat out of this lawsuit and this young man's family. They will be lucky if they are not countersued. (Common tactic in this type of case).