Newlyweds Beyzanur Beyazıt and Ali Karaca were being escorted home after the ceremony when Karaca was wounded by gunfire, allegedly at the hands of his sister-in-law.
Hollywood actor Leo, 50, and modal Vittoria, 27, know their way around the ship, having previously joined the couple and bevy of stars for a trip last summer.
Newlyweds Camille Rosenfeld, from Minnesota in the US, and James Hayes, from Tralee in Co Kerry, will live simple lives as caretakers on the rugged island from April 1 to September 31.