Every time you enter the water there is always the chance you could be viciously attacked by a shark even if you're in a pool someone could drop a shark in there when you're not looking. So what do you do when a shark grabs hold of you? Most people say you should try to gouge its eyes out. I'm not sure that works, but if anything that will blind the shark so it's harder for it to attack people in the future after you're dead. It would seem that the only reason sharks attack people is because they mistake the person for a seal. So to survive a shark attack you need to do the exact opposite of what a seal does. That means DON'T struggle. Just go limp in the shark's mouth. Normally going limp in someone's mouth is not what you're taught to do, but in this case it's fine. Then that can confuse the shark and your next move is to try to keep it from biting open a main artery and hope for it to let you go. This is what happened to some fool recently:
Tom Kennedy of Lake Oswego, Ore., was snorkeling near a shore in Kihei, Hawaii at about 9:35 a.m., when a 10 foot shark attacked him. Kennedy said at some point, the shark let go of his leg and he swam as fast as he could to get away. "It released me and I started swimming as fast as I could…as I went further and started to bleed, I could see I was trailing blood, which was my next concern," Kennedy said.
This is the key, when it lets you go you need to swim as fast as possible. Don't just swim all slow and take your time. You're gonna really want to put your all into it, that means arms AND footsie paddling. You're going to worry about all the blood loss, but do that later on the shore. Don't dwell on that while the shark is still near, that's a bad move. So to recap, go limp, keep your thigh out of the shark's mouth, and swim as fast as you can when it lets you go.