We were on a cruise ship. Tiff was wanting to go with friends. said no to casino, she went anyway, text her she in trouble. next morning, she wanted to go ashore or in water with lauren and Ashley. I asked what the theme for the day was, she was just ready to go, didn't look at book, after they left the room, I looked and there was a party I knew she's want to go to later, so I went out on deck/balcony and I could see them getting in the water or in the water already, and I hollered for her to come back, she fussed, I finally said "if you don't come here right now, im going to say no you cant go because there is something you are going to want to go to. she finally headed back to the mesh dock, as did the other two girls, when I saw a fin pop up, circle, then head towards tiff. I didn't say anything because I thought they would be out of the water in time but it got closer quicker and I started yelling for the other girls to get out of the water because tiff was already at the dock and they weren't (they were on boogie boards or body boards or something) but the shark ignored them and went for tiff and got her. I started screaming for the other girls to help her and screaming shark, and the girls tried to hit the shark, nobody else came to help her, I was helpless and felt miles away seeing her in this sharks mouth and I couldn't stop it. the shark ended up biting her left leg off below the knee. I woke up just as they pulled her up on the dock and i saw her leg. mouth dry, heart beating.