Stranded (Alaskan Courage, #3) by Dani Pettrey - March 5, 2017

[Megan]

When her friend vanishes from a cruise ship, reporter Darcy St. James isn't satisfied with their explanation that she simply left her job of her own accord. Something isn't lining up, and Darcy believes the only way to find the truth is to put herself in Abby's position. Within days, Darcy learns her friend wasn't the only person to disappear mysteriously. Last summer, a woman vanished under almost identical circumstances.
Gage McKenna has taken a summer-long stint leading adventure excursions for the passengers of various cruise lines that dock for a few days of sightseeing. He's surprised to find Darcy working aboard one of the ships, investigating a troubling report. Something sinister is going on and the deeper they dig the more Gage fears they've only discovered the tip of the iceberg.