Cruise expert Professor Ross Klein’s website refers to a case of an Israeli passenger who went overboard in the Mediterranean Sea during a vacation cruise earlier this month.
According to the Y News Net newspaper in Israel, the passenger was identified as a 43 year old Israeli taxi driver from Hadera who did not return
Professor Ross Klein’s CruiseJunkie website reports a passenger is missing from the Solstice cruise ship, operated by Celebrity Cruises. Another passenger notified the CruiseJunkie website 
that a passenger may have jumped from the cruise ship on November 6th:
I’m a passenger on Celebrity Solstice between Santorini and Naples. At 9PM local time tonight, a female passenger jumped purposefully from Deck 14. She
A 67-year-old passenger is the latest "disappearance" from a cruise ship. This case involves a U.S. citizen who sailed on Princess Cruises’ cruise ship Sapphire Princess from Alaska en route to Vancouver. She has not been identified.
According to Dr. Ross Klein, the leading authority on passenger disappearances in the world , there have been over 120 "disappearances" from cruise ships over the past
