I agree with other reviewers that it's hard to find the true story of the crimes shown in this show. But I've found a few.
The episode listed as ASHLEY is really about Karen Waltz Roston, who was killed on the ship "Stardancer" in 1988 by her new husband, Scott Ralston, while they were on their honeymoon.
GEORGE was about George Smith IV, who disappeared from the cruise ship, "Brilliance of the Seas," in 2005 while on his honeymoon with his new wife, Jennifer, in mysterious circumstances. Blood was found on a canopy below their cabin, & Jennifer was found in a far away hallway, where she had apparently been sleeping all night. Case was never solved. Amazed they used his real 1st name.
AMY was about Amy Lynn Bradley who went on cruise with her parents & brother on the "Rhapsody of the Seas" in 1998 & vanished without a trace. Again correct name was used.
MERRIAN was about Merrian Carver, who disappeared off a Celebrity cruise ship in 2004.
MURIEL is about Muriel Collins Barnett. killed by her assistant with a wine bottle on the "Royal Viking Star" in 1989. Same name again.
SADIE is about Lynne Kauffman murdered on the SS Utrecht in 1959 allegedly by her lover, Willem van Rie. He confessed then retracted. Found not guilty at trial.
BETSY is about Jessie Harper Mozee, who was robbed, killed & dumped overboard on the "SS C & B" in 1940. Never solved but her maid was suspected of at least the robbery.
SHELLY is about Yang Wenjuan, a PhD teacher, who was murdered on the "MV Macau Success" by her husband, Wang Weilie, when he threw her overboard & was witnessed by a passenger on the deck below. Although contemplating divorce, they stayed together for the sake of their 9-yr-old child. Her body was found & revealed she had been battered.
Those are the only ones I can find. If anyone has more, please post on this board.