Well, here's a picture of my S2 rig with the front of the housing taken off:

You can see the housing, 2 arms, sync cord, and two strobes.
Here's a picture of the housing w/ the front on and the macro/flat port:

Here's a picture of the back:

On the front of the housing you can see the controls for the Aperture, and the on-off lever as well as the shutter release.
On the back you can see the shutter speed control (right side) as well as Ike's sportfinder. The knob on the top is for the EV +/- and the Flash +/-
In the lower left you can see the LCD display which is unobstructed. The knobs on the left side control flash mode and bracketting. The second knob on the left controls the camera - you can switch from Manual to A or S underwater. You can also change ISO and custom settings underwater.
FWIW, my photos AND my technique have improved about 100x since I upgraded from a consumer level UW system.
Cheers
James