All these photos were taken with a Nikon F80s w/ Sigma 8mm/4, Nikkor 16mm/2.8 fisheye and/or Nikkor 105mm, for the flash I use one YS-90 and one YS-120.
The eye pic was taken with a Hugyfot housing, the others are with a NX-80 Sea&Sea housing.
Of them the eye is the only double-exposure, as it shows on the blue reflex of the macro port and the flash relex on the eye. The diver is just the 8mm inside the dome with the flashes advanced in front of the housing. The vertical one is the 8mm with and adaptaion (I had to cut the dome shades!!!) and I did cut the film in the "wrong" point to make the circle drop to the bottom.