Great photos,...and extreme dynamic range. One thing I do when I have this much DR, (and this is really for those concerned with "sucking" detail, even when it is not artistically required...but let's not get into that discussion), is I transfer the RAW file as shot, then transfer the same shot with exposure compensation slider 2 stops under, then do same with slider 2 stops over. Then layer these 3 tif files, and adjust transparency on the over and under layers, (and maybe erase portions) This extends the already 5-6 stops of DR to about 10.
Obviously that's a lot of work but it might be worth it for a few of those underwater shots.
Cheers
James