The New York Times has a nice profile of the photographers at the Olympic Games who bring us the underwater images. I had no idea they were certified scuba divers!

Sports photographers who shoot underwater used to free-dive to make these adjustments; now many, including Bello, Rose and Pretty, are certified scuba divers. That has given them the comfort of extended time underwater to perfect the art of capturing the world’s best swimmers from below. But it also leads to an odd sight every night at the London Aquatics Centre: a glass-and-plastic reef composed of 10 cameras and a platoon of frogmen who enter the pool soon after the last race to tend to them.

Preparation is everything:

Preparation is everything. Each camera has to be set up to focus on a specific race, or perhaps two lanes where a close finish is expected. Sometimes a camera will wait all day for a specific swimmer to splash into frame.

They use a handheld trigger to operate the shutter. It’s connected, via cable, to the camera at the bottom of the pool. Now that cameras are all digital, almost as soon as they are taken, the images can be viewed on a laptop.

Also worth reading is this post on Rob Galbraith’s blog, who interviewed Clive Rose before the Olympics on his camera equipment and set-up:

We [Getty Images] have been working with Canon on an underwater photography solution for the London Olympics for some time now, so we were lucky enough to be able to use a pre-production EOS-1D X with the new EF 8-15mm f/4L Fisheye USM lens during the test event. This was packed inside a prototype custom built waterproof housing. 

The EOS-1D X isn’t even available yet (or wasn’t then), so getting a housing to fit was one of the many challenges that we’ve had to deal with. The housing is connected via hardwire cables that run from the back of the housing along the pool floor to a laptop at poolside. There, we can use Live View to adjust the camera settings to suit which kind of shot we want. The camera is powered (always on) and connected to an Ethernet cable to allow us to draw the images up in real time. We can fire the camera either via the laptop through the Live View software, or hook the camera up to a trigger cable and attach the end of that to a PocketWizard, much the same way as you would for any other remote camera.