In SE Florida, we occasionally get harassed by sharks usually taking all, or a bite out of our catches.
On several occasions, I have been followed by Hammerheads for up to 30 minutes. A few times they have rammed my kayak, one time charging and turning at the last moment to soak me with a tail lash of water.
Thankfully they have never taken a bite on the yak, but I carry duct seal and flex tape in case of an unexpected hole. There is a youtube video of an instance when a hammerhead did bite a kayak, but thankfully the tooth marks were minor. My worse loss up to now has been the tail half of a nice wahoo, the shark bumped the kayak a few times after I pulled the fish out of the water before swimming off.