Ian Redmond, 30, from Lancashire, was attacked as he swam off Anse Lazio beach on the island of Praslin.
His new wife, Gemma Houghton, was onshore and watched while another tourist brought Mr Redmond to shore on a dinghy.
“We heard screaming and people started running down the beach towards the water,” one American tourist told The Daily Mail Newspaper.
“Someone had seen a fin sticking out of the water, and then we saw a dinghy pulling a man from the water.”
“I saw the swimmer, who was missing a huge chunk of flesh from his left leg, so much so that I could see the bone of his thigh. He was sickeningly pale, but still had his flippers on both feet.
“At this point a woman ran over and started screaming. She said: ‘That’s my husband! We were just married.’
“Someone grabbed her and tried to keep her away. People all over the beach were just hugging whoever was close to them or trying to keep any children from witnessing what was going on.”
The attack comes less than a fortnight after a French tourist was fatally bitten in waters off the same island.
Prince William and Kate Middleton spent their 10-day honeymoon there but were not eaten by sharks. We felt it was important you knew that. Sharks having respect for royalty – thats what it is all about. Better beware of a republican shark though wills.