High Altitude Scuba Photography Cautions!

After diving Mirror Lake and Trial Lake, we had water in the film compartments of two cameras, and water in the strobe connector of one. I had loaded the film at home, so I wouldn't have to load the cameras at the windy, wet, dirty lake. It sounded like a great idea. Big mistake. Here's why:

The O-ring on your camera (or housing) depends on the pressure of the water to keep a good seal. That's why scuba camera manufacturers don't recommend using your camera when snorkeling -- the water pressure isn't high enough to make a good seal.

When I loaded the film at home, I sealed the camera. Arriving at 9000 feet, there was higher pressure inside the camera than outside. This moved the O-ring and slightly opened the crack between the back cover and the camera body. Then two things happened: (1) sand and crud got into the crack, so even when I got down to a depth where the water pressure was greater than the pressure in the camera, the back didn't fit tightly, and (2) at the depth where the water pressure equaled the pressure in the camera, there was no seal at all, so water could "wick" past the O-ring.

The camera that leaked at the strobe connector had been assembled at home -- I put it in the camera box with the strobe already attached for its trip to high altitude.

I was lucky. Only a few drops got into the cameras. After a couple of days under a drying lamp, the cameras are working fine. Our only loss was some ruined pictures.

Take home message:

(1) Clean and lube your O-rings between each roll of film.

(2) Either insert your film at the dive location, or (if you're in the middle of a roll) "vent" the camera before submerging it. (The Nikonos can be vented by removing the lens. To vent the Sea & Sea, insert it in a black bag and open the back just enough to hear it hiss, then reseal it.)

(3) Assemble all O-ring protected parts at the dive site, not at home.