Thank you everyone for the great responses and the very helpful image links. Talk about envy, I can't wait to dive with those beauties and get half the results you fine photographers did. You've given me more to work out.
I do plan to bring strobes just in case. I figured that if there were two or three of us in the cage and we all had strobes, I'd prefer to be more flexible and less obrusive and go without using them, perhaps bringing them out on the last day or so when everyone has a routine established.
I have not yet invested in the 17-55 but was able to use it (and a 70-200) at a recent concert and found it really nice. Though expensive, the only real doubt I had was whether it was wide enough? It sounds as though you all are quite please with some of the alternatives that the 12-24 and tokina 10-17 can provide. With the tokina at 17 on my cropped D200 the fishy look would be minimized to a degree, but not enough to be as much of a value to me topside, but I could always leave it dedicated to u/w use. My main reason for the thought on the 17-55 was that if the sharks were not interested enough and were keepign a distance that I would have some range there to try and pull them in a little tighter with that lens. Not having past experience with the area, I kind of planned for a lot of hit or miss opportunities. I realize the crew will do their best to draw them in, but in your experience, is it about 50/50 that the sharks will get close enough or better? If they are know to get much closer I think one could go wider.
A few other questions if you would please entertain, though I don't want to go too far off lens topic. Personally, I have no problems with sharks or demanding dive situations, and I would really like to capture some of the out of the cage images such as Mike was able to get. The operator is not suggesting bringing dive equipment, leaving everything hooka based and I am unaware if they permit out of the cage dives? Do you find it possible to do this? Woulld you suggest brining some equipment and ask (kindly/beggingly) upon arrival and once I've proven my competence and experience to the crew? Any suggestions?
Thank you for the tips and help!