I am interested in getting a housing for my Canon EOS 1Ds Mark III. I also have a 1D Mark III and it would be nice if I could use the same housing for either camera - near the surface the high frame rate of the 1D Mark III might be useful.
Likely lenses would be Canon 14mm II, 15mm fisheye, 16-35mm II, 50mm macro, 100 mm macro. I would want the housing, a very large dome port, perhaps a smaller dome port or flat port, and probably a macro lens port, and of course flash arms. I believe that I would want to get one of the accessory optical viewfinders also.
Subal offers a Mark III housing Subal seems to get high marks from everybody, and would seem like a reasonable choice. They have a nice looking optical viewfinder, and all of the other major accessories. Despite looking at lots of data I am unclear if there are any unique advantages to Subal.
Aquatica housings also have their advocates, as with Subal I don't know what is uniquely great about their housing.
Same story with Sea & Sea. Their optical viewfinder does not seem to be as big (or expensive) as the Subal / Aquatica / Seacam viewfinders so I wonder if it is comparable. This might be a slight negative for them.
Nexus does not seem to offer Canon housings, at least that I can find on their website.
Seacam says they will have a Mark III housing in 2008 - it is unclear from the web site whether it is already shipping, or not. I have a big dive trip planned for December, so that may eliminate them, or may not if it comes out soon.
I am very intrigued by the Seacam polecam set up. It is wickedly expensive, but looks like it could be great for some things, like photographing billfish when they come up to the boat before being released, or sharks on the surface.
I plan on using 6-wire connectors such as the S6 flash port so that I have the option of using ETTL flash. Seacam touts it as an exclusive, but I think I can get S6 ports, or functionally equivalent 6-wire ports in any housing, can't I? Sea & Sea offers their own version of 6-wire, which may or may to be plug compatible, but it must be electrically the same.
The pole cam and the S6 ports do seem to give Seacam a technology edge. On the other hand it seems to easily be the most expensive housing. Indeed the Seacam is 1.5X more expensive than the Sea & Sea, and 1.9X as much as the Aquatica. So, I could get most of the way to two of the cheaper housings for the same cost. That said, I can afford the Seacam if it really better in a way that I would notice.
I have not seriously looked at other housings, but if there are some I should consider let me know.
So, how do I decide between these choices. I think that any of them would probably work, but I want to try to make the best, or anyway, best educated choice. This might be special features, or special accessories not found elsewhere, or things that work better on one versus another.