After some 200+ shark encounters with various spieces, I have never felt threatned by sharks. Encounters that have been a bit more "exciting" than others have been with open water spieces like silkys and oceanic whitetips. Especially when snorkeling - you feel a bit more vurnurable when you're on the surface with no bottom in sight and someone is yelling from the boat - HE'S BEHIND YOU! 
But I have still to meet a tiger or a White Shark. But if I felt seriously threatened, I would try to get out of the area (read further down why sharks get aggressive) and out of the water, keeping an eye on the shark and my back towards the reef if possible.
However, the strangest behaving shark I have met, which also was a bit aggressive, was a scalloped hammerhead, a female. I have been diving with scalloped hammerheads many times, schooling ones as well as smaller groups of animals. Usually they are very timid and shy away, keeping their distance. This was in the sudanese Red Sea of the south west point of Sanganeb Atoll near Port Sudan. We had spent a few days of diving this place and a school of 30-40 specimen were present on most dives. On this particular dive, me and my girfriend went out to the point were the reef drops off into the abyss. The school was deeper down on the the edge of the viz.-range. One female shark however brakes away from the school and starts to swim straight at us. I had my camera ready and thought GREAT! since good hammerhead pictures are very hard to get. Unfortunatelly the shark picks my girlfriend instead of me, so I didn't come as close as she did. This lady swims rapidly and erratic, not the gentle movements which one usually connects with the hammerheads. Allthough I didn's see it, my girlfriend claims she had to kick the shark in the head before it went back to the school (I guess i was busy with the camera).
I have one picturure of the shark with my girlfriend in the background (on the right almost in the bottom), also some other sharkie and dive pics here:
http://www.dykarna.nu/photoAlbum/album.asp?userId=4389&albumId=1112
Also, I would like to say a few words about the mistaken identity theory. This theory is based upon that the attack have to do with feeding. The majority of attacks (which are quite few each year when you realise how many people entering the water) doesn't have anything to do with feeding. When a dog attacks a man, it is not because it want's to eat him. Same with sharks. It seems more likely that it is territorial defence, a curious sharks (a shark examine by tasting) or maybe many times, like stated in this thread by Rick and Vicky and some others, herrassed or fired up (by bait) sharks. Taking into account that sharks have highly evolved senses, smelling and also vision, it just doesn't make sense they would mistake a human for a seal or a fish.
Cheers
Christian
But I have still to meet a tiger or a White Shark. But if I felt seriously threatened, I would try to get out of the area (read further down why sharks get aggressive) and out of the water, keeping an eye on the shark and my back towards the reef if possible.However, the strangest behaving shark I have met, which also was a bit aggressive, was a scalloped hammerhead, a female. I have been diving with scalloped hammerheads many times, schooling ones as well as smaller groups of animals. Usually they are very timid and shy away, keeping their distance. This was in the sudanese Red Sea of the south west point of Sanganeb Atoll near Port Sudan. We had spent a few days of diving this place and a school of 30-40 specimen were present on most dives. On this particular dive, me and my girfriend went out to the point were the reef drops off into the abyss. The school was deeper down on the the edge of the viz.-range. One female shark however brakes away from the school and starts to swim straight at us. I had my camera ready and thought GREAT! since good hammerhead pictures are very hard to get. Unfortunatelly the shark picks my girlfriend instead of me, so I didn't come as close as she did. This lady swims rapidly and erratic, not the gentle movements which one usually connects with the hammerheads. Allthough I didn's see it, my girlfriend claims she had to kick the shark in the head before it went back to the school (I guess i was busy with the camera).
I have one picturure of the shark with my girlfriend in the background (on the right almost in the bottom), also some other sharkie and dive pics here:
http://www.dykarna.nu/photoAlbum/album.asp?userId=4389&albumId=1112
Also, I would like to say a few words about the mistaken identity theory. This theory is based upon that the attack have to do with feeding. The majority of attacks (which are quite few each year when you realise how many people entering the water) doesn't have anything to do with feeding. When a dog attacks a man, it is not because it want's to eat him. Same with sharks. It seems more likely that it is territorial defence, a curious sharks (a shark examine by tasting) or maybe many times, like stated in this thread by Rick and Vicky and some others, herrassed or fired up (by bait) sharks. Taking into account that sharks have highly evolved senses, smelling and also vision, it just doesn't make sense they would mistake a human for a seal or a fish.
Cheers
Christian
