The North Rock camera is a small, high quality video camera that is mounted on a special device called a "pan and tilt unit" or PTU. The PTU actually is the part that moves the camera in a nearly complete circle (panning) and also tilts it so that you can see almost a complete sphere. Another feature of the camera is the ability to zoom in and out.
As you can see in the picture, the camera, PTU and other electronics sit inside a plexiglass housing. The electrical wires end or terminate in "thru-the-hull" connectors that let us connect the entire housing to the underwater cable with removable connections that work underwater. This is a critical component of the design because any leakage, allowing flooding inside the unit or water entry into the cable connection, would be disastrous. Since seawater conducts electricity so well (and is very corrosive), any water in the joint would cause a short-circuit.
The cable runs from the camera back to North Rock and connects to the microwave transmitter. Although it is secured to the hard coral or submerged under sand where possible as it travels from the camera, the outside is armored to prevent damage from fish bites (!) and from chafing or rubbing as the waves move the cable around. Inside the armor is insulation to keep the seawater out and then several wires. Wires carry power and control signals to the camera and PTU and different wires carry the video signal back to be transmitted.
The software to put the video signal on the Internet, enables you to view it on your computer, and to move the camera remotely is created by Perceptual Robotics Inc. You can check out their site for links to other cameras around the world.
The software takes the video signal and "digitizes" it or makes it into a form of 1's and 0's that the computer can use. It then transmits it over a special cable (an ISDN line) to another computer which puts the signal onto another line to the US where it is actually seen by all of you!