Thank you very much guys for all the compliments. Alex, I do think that high ISO will allow us to do more underwater than we think. It's more than just being able to capture the image without noise, it's also about opening up shadows and midtones. The D700 has changed the way I do topside photography, and I think it may change a lot of what I do underwater.
Carol, you are right, conditions were great, and I suspect high ISO will be even more helpful if used properly, in less ideal conditions. The worse the conditions, the more our strobes degrade the image.
Mauricio Handler, who I think has a great approach to ambient light photography, is all about using using strobes only to paint in the bare minimum of light that we need to add for an effective photograph.
This is why I think we may be deluding ourselves a little when we try to get the best high ISO performance and the highest possible MP at the same time. My approach is actually to use the least number of megapixels to provide the resolution that I need for my final output, this will give me the largest pixels. A landscape photographer I know actually demonstrated this to me once by comparing images from a D40 with a D40x. But thats all for another discussion.