I currently use the Canon EOS 7D. Before the 7D, I used Canon EOS 5DM2, but did not like it much for underwater photography.
For underwater macro I mainly use the EF-S 60 mm as it is very sharp, has a short minimum focus distance, is quite versatile and focuses very quickly. For skittish creatures I use EF 100/2,8 L macro. For macro on land I use the MP-E 65, the EF 100/2,8 L macro and the EF 180/3,5 L macro depending on subject and how much enlargement I want.
For underwater wide angle I mainly use the EF 8-15 L fisheye zoom with the Zen mini dome . On rare occasions, where straight lines really should be portrayed straight, I use the EF-S 10-22 or the EF 17-40 L behind Nauticam´s 8 inch dome.
For land wide angle I use the same lenses as for underwater wide angle. For tele I use EF 70-200 2,8 L, EF 70-300 L, EF 400 5,6 L and EF 300/2.8.
I have a number of different sized Canon Speedlites for land shooting as well as Canons MT 24 EX twin lite flash for macro.
I use Nauticams housing fitted with Nauticam´s 45 degree viewfinder and Nauticam ports.
I use two Inon Z 240 strobes with optical wiring. I will soon add one more Inon to my set up.
I use the original Sola 600 as focus light.
When shooting fluorescence underwater I use Sola´s package including a Night sea light, filters for the Inon strobes and filter for the port. Also I use a yellow filter mounted on the dive mask to be able to see the fluorescence.