I don't know about any studies, but there have been some posts regarding sharks. Check these out
http://forum.treasurenet.com/index.php/topic,88755.0.html
http://forum.treasurenet.com/index.php/topic,65858.0.html
Whether you're hitting shallow or deep water, there are certain things you should remember (as a recap)
1. Try to avoid splashing, erattic motions, etc... usually a sign of distress (aka lunch)
2. Watch for the little baitfish... when they are "running" something is usually chasing them
3. ... goes along with # 2... don't wear anything shiny/dangly. It looks like batifish (aka lunch)
4. no open cuts... blah blah blah... (blood in the water = bad)
5. pay attention to your surroundings (a good set of polarized glasses is a good idea)
6. stay out of the water at night. Dusk, dawn and dark are feeding times. I'd also throw murky water into this category
7. Regardless of what happens - never panic. panic/fear is sensed by most animals
8. Most shark attacks are mistaken identity... (see #'s 1,3,4) they don't really like how we taste
And as tom (wreckdiver) says... just make sure you can swim faster than your dive/hunting buddy.
A lot also depends on where you're hunting. Oh... and if you're in florida (or any other alligator/croc infested areas, the same holds true with them.
I wrote this with a little bit of humor... just use your common sense. Most of these rules hold true. Remember, they are wild animals and as such, fairly unpredictable.
steve