Ian Redmond, 30, and his new bride Gemma Houghton, 27, were honeymooning in Anse Lazio, a beach in the north of Praslin Island, Seychelles.
Houghton was sunbathing on the beach and Redmond snorkeling in the crystal blue waters when she heard his frantic cries for help.
Witness pulled him to shore, but it was too late. In an instant, Houghton went from new wife to young widow.
Authorities believe it was a bull shark that attacked Redmond, possibly the same animal that killed a French tourist on the beach just two weeks ago.
The deaths are the first in the idyllic waters around the Seychelles in almost 50 years.
The islands are a popular destination for British tourist, including Prince William and Kate, who spent their honeymoon earlier this year on a nearby private island.
According to the BBC, shark experts from South Africa were planning on going to the scene to identify and hopefully catch the shark.