I got some black tape before xmas, need to get it in place and then it's time to get under the ice again to test if it works. BTW, the strobes were about 10 cm behind the dome and in a low(ish) position, 40 cm from the housing.
Looking at your collection of lenses, I would also recommend looking at the D7100 if you want to stay on crop format. I'm shooting Canon (550D) and my upgrade in 2015 will be either the new 7D mkII (depending on what the reviews will show) or then just housing my "surface camera" 5D mkIII. My wife will of course kill me if I house the 5D, because then I have to buy a new camera for surface photos.